642 lines
21 KiB
JSON
642 lines
21 KiB
JSON
{
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"meta": {
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"instanceId": "408f9fb9940c3cb18ffdef0e0150fe342d6e655c3a9fac21f0f644e8bedabcd9",
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"templateCredsSetupCompleted": true
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},
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"nodes": [
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{
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"id": "0c49141e-128c-424e-afdf-ea131b7a3dd8",
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"name": "GetTableSchema",
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"type": "n8n-nodes-base.postgresTool",
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"position": [
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-460,
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220
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],
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"parameters": {
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"query": "SELECT column_name, data_type FROM information_schema.columns WHERE table_name = $1",
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"options": {
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"queryReplacement": "={{ $fromAI('tableName', 'The name of the table.') }}"
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},
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"operation": "executeQuery",
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"descriptionType": "manual",
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"toolDescription": "Read a table's schema."
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},
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"credentials": {
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"postgres": {
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"id": "elRn5sxKOfCdlEs6",
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"name": "Postgres account"
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}
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},
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"typeVersion": 2.6
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},
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{
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"id": "8ffeefb9-357c-41bc-8239-0c07c706be97",
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"name": "ListTables",
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"type": "n8n-nodes-base.postgresTool",
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"position": [
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-340,
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300
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],
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"parameters": {
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"query": "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'",
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"options": {},
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"operation": "executeQuery",
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"descriptionType": "manual",
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"toolDescription": "List all available tables."
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},
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"credentials": {
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"postgres": {
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"id": "elRn5sxKOfCdlEs6",
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"name": "Postgres account"
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}
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},
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"typeVersion": 2.6
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},
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{
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"id": "efcf7ff3-976e-448a-9d47-47a98f3b0fcb",
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"name": "When Executed by Another Workflow",
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"type": "n8n-nodes-base.executeWorkflowTrigger",
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"position": [
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280,
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200
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],
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"parameters": {
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"workflowInputs": {
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"values": [
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{
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"name": "operation"
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},
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{
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"name": "tableName"
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},
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{
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"name": "values",
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"type": "object"
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},
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{
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"name": "where",
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"type": "object"
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}
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]
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}
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},
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"typeVersion": 1.1
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},
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{
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"id": "abd292d7-fc2b-4e98-a474-b50e44d16b6c",
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"name": "CreateTableRecords",
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"type": "@n8n/n8n-nodes-langchain.toolWorkflow",
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"position": [
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-240,
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400
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],
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"parameters": {
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"name": "CreateTableRows",
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"workflowId": {
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"__rl": true,
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"mode": "id",
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"value": "={{ $workflow.id }}"
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},
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"description": "Call this tool to create a row in the database.",
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"workflowInputs": {
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"value": {
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"where": "={{ {} }}",
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"values": "={{ /*n8n-auto-generated-fromAI-override*/ $fromAI('values', `An object of key-value pair where key represents the column name.`, 'string') }}",
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"operation": "insert",
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"tableName": "={{ /*n8n-auto-generated-fromAI-override*/ $fromAI('tableName', `Name of table to update`, 'string') }}"
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},
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"schema": [
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{
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"id": "operation",
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"type": "string",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "operation",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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},
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{
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"id": "tableName",
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"type": "string",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "tableName",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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},
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{
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"id": "values",
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"type": "object",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "values",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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},
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{
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"id": "where",
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"type": "object",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "where",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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}
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],
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"mappingMode": "defineBelow",
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"matchingColumns": [],
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"attemptToConvertTypes": false,
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"convertFieldsToString": false
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}
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},
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"typeVersion": 2.1
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},
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{
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"id": "4a71d42a-99a5-489e-b449-09c3c5081505",
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"name": "ReadTableRecord",
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"type": "n8n-nodes-base.postgres",
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"position": [
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760,
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0
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],
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"parameters": {
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"query": "SELECT * FROM {{ $json.tableName }}\n{{ $json.where && Object.keys($json.where).length > 0\n ? `WHERE ` + Object.keys($json.where).map((key,idx) => `${key} = $${idx+1}`).join(' AND ')\n : ''\n}}",
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"options": {
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"queryReplacement": "={{ Object.values($json.where).join(',') }}"
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},
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"operation": "executeQuery"
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},
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"credentials": {
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"postgres": {
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"id": "elRn5sxKOfCdlEs6",
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"name": "Postgres account"
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}
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},
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"typeVersion": 2.6,
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"alwaysOutputData": true
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},
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{
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"id": "bdc60aa8-9ab1-4bbd-8b9e-89c968d54043",
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"name": "Operation",
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"type": "n8n-nodes-base.switch",
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"position": [
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460,
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200
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],
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"parameters": {
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"rules": {
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"values": [
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{
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"outputKey": "READ",
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"conditions": {
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"options": {
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"version": 2,
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"leftValue": "",
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"caseSensitive": true,
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"typeValidation": "strict"
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},
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"combinator": "and",
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"conditions": [
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{
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"id": "81b134bc-d671-4493-b3ad-8df9be3f49a6",
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"operator": {
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"type": "string",
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"operation": "equals"
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},
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"leftValue": "={{ $json.operation }}",
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"rightValue": "read"
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}
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]
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},
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"renameOutput": true
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},
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{
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"outputKey": "INSERT",
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"conditions": {
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"options": {
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"version": 2,
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"leftValue": "",
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"caseSensitive": true,
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"typeValidation": "strict"
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},
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"combinator": "and",
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"conditions": [
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{
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"id": "8d57914f-6587-4fb3-88e0-aa1de6ba56c1",
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"operator": {
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"name": "filter.operator.equals",
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"type": "string",
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"operation": "equals"
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},
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"leftValue": "={{ $json.operation }}",
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"rightValue": "insert"
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}
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]
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},
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"renameOutput": true
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},
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{
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"outputKey": "UPDATE",
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"conditions": {
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"options": {
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"version": 2,
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"leftValue": "",
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"caseSensitive": true,
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"typeValidation": "strict"
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},
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"combinator": "and",
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"conditions": [
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{
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"id": "7c38f238-213a-46ec-aefe-22e0bcb8dffc",
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"operator": {
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"name": "filter.operator.equals",
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"type": "string",
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"operation": "equals"
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},
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"leftValue": "={{ $json.operation }}",
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"rightValue": "update"
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}
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]
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},
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"renameOutput": true
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}
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]
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},
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"options": {}
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},
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"typeVersion": 3.2
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},
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{
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"id": "cdb5b556-3638-4fa5-94c6-bff0c03f6c89",
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"name": "UpdateTableRecord",
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"type": "n8n-nodes-base.postgres",
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"position": [
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760,
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400
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],
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"parameters": {
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"query": "UPDATE {{ $json.tableName }}\nSET\n {{ Object.keys($json.values)\n .map((key,idx) => `${key} = $${idx+1}`)\n .join(',')\n}}\nWHERE\n {{ Object.keys($json.where)\n .map((key,idx) => `${key} = $${idx+Object.keys($json.values).length+1}`)\n .join(' AND ')\n}}",
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"options": {
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"queryReplacement": "={{ Object.values($json.values).join(',') }},{{ Object.values($json.where).join(',') }}"
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},
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"operation": "executeQuery"
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},
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"credentials": {
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"postgres": {
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"id": "elRn5sxKOfCdlEs6",
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"name": "Postgres account"
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}
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},
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"typeVersion": 2.6
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},
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{
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"id": "9263fc78-321e-4c83-90d3-890dd87d6aed",
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"name": "UpdateTableRecords",
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"type": "@n8n/n8n-nodes-langchain.toolWorkflow",
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"position": [
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-100,
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320
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],
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"parameters": {
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"name": "UpdateTableRows",
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"workflowId": {
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"__rl": true,
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"mode": "id",
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"value": "={{ $workflow.id }}"
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},
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"description": "Call this tool to create a row in the database.",
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"workflowInputs": {
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"value": {
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"where": "={{ /*n8n-auto-generated-fromAI-override*/ $fromAI('where', `An object of key-value pair where key represents the column name.`, 'string') }}",
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"values": "={{ /*n8n-auto-generated-fromAI-override*/ $fromAI('values', `An object of key-value pair where key represents the column name.`, 'string') }}",
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"operation": "=update",
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"tableName": "={{ /*n8n-auto-generated-fromAI-override*/ $fromAI('tableName', `Table to update`, 'string') }}"
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},
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"schema": [
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{
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"id": "operation",
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"type": "string",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "operation",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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},
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{
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"id": "tableName",
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"type": "string",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "tableName",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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},
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{
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"id": "values",
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"type": "object",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "values",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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},
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{
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"id": "where",
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"type": "object",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "where",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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}
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],
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"mappingMode": "defineBelow",
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"matchingColumns": [],
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"attemptToConvertTypes": false,
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"convertFieldsToString": false
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}
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},
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"typeVersion": 2.1
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},
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{
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"id": "dd7e28fb-b2c7-4084-bc9b-9aa3e0187682",
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"name": "CreateTableRecord",
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"type": "n8n-nodes-base.postgres",
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"position": [
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760,
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200
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],
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"parameters": {
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"query": "INSERT INTO {{ $json.tableName }}\n ({{ Object.keys($json.values).join(',') }})\nVALUES\n ({{ Object.keys($json.values).map((_,idx) => `$${idx+1}`).join(',') }})",
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"options": {
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"queryReplacement": "={{ Object.values($json.values).join(',') }}"
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},
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"operation": "executeQuery"
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},
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"credentials": {
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"postgres": {
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"id": "elRn5sxKOfCdlEs6",
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"name": "Postgres account"
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}
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},
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"typeVersion": 2.6
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},
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{
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"id": "324503c0-117b-45ec-97dd-7074eb1db22e",
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"name": "ReadTableRows",
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"type": "@n8n/n8n-nodes-langchain.toolWorkflow",
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"position": [
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20,
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240
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],
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"parameters": {
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"name": "ReadTableRows",
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"workflowId": {
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"__rl": true,
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"mode": "id",
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"value": "={{ $workflow.id }}"
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},
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"description": "Call this tool to read a row in the database.",
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"workflowInputs": {
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"value": {
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"where": "={{ /*n8n-auto-generated-fromAI-override*/ $fromAI('where', `An object of key-value pair where key represents the column name.`, 'string') }}",
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"values": "{}",
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"operation": "read",
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"tableName": "={{ /*n8n-auto-generated-fromAI-override*/ $fromAI('tableName', ``, 'string') }}"
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},
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"schema": [
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{
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"id": "operation",
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"type": "string",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "operation",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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},
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{
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"id": "tableName",
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"type": "string",
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "tableName",
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"defaultMatch": false,
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"canBeUsedToMatch": true
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},
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{
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"id": "values",
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"type": "object",
|
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"display": true,
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"removed": false,
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"required": false,
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"displayName": "values",
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"defaultMatch": false,
|
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"canBeUsedToMatch": true
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},
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{
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"id": "where",
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"type": "object",
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"display": true,
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"removed": false,
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"required": false,
|
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"displayName": "where",
|
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"defaultMatch": false,
|
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"canBeUsedToMatch": true
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}
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],
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"mappingMode": "defineBelow",
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"matchingColumns": [],
|
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"attemptToConvertTypes": false,
|
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"convertFieldsToString": false
|
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}
|
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},
|
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"typeVersion": 2.1
|
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},
|
|
{
|
|
"id": "9cf39ca3-b704-49ce-b6e2-db2703c4acad",
|
|
"name": "Sticky Note",
|
|
"type": "n8n-nodes-base.stickyNote",
|
|
"position": [
|
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-520,
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-120
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],
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"parameters": {
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"color": 7,
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"width": 680,
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"height": 660,
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"content": "## 1. Set up an MCP Server Trigger\n[Read more about the MCP Server Trigger](https://docs.n8n.io/integrations/builtin/core-nodes/n8n-nodes-langchain.mcptrigger)"
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},
|
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"typeVersion": 1
|
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},
|
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{
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"id": "ac3d9b98-8f1e-4abd-972c-1725aac1ad1e",
|
|
"name": "PostgreSQL MCP Server",
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"type": "@n8n/n8n-nodes-langchain.mcpTrigger",
|
|
"position": [
|
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-340,
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20
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|
],
|
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"webhookId": "a5fd7047-e31b-4c0d-bd68-c36072c3da0d",
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"parameters": {
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"path": "a5fd7047-e31b-4c0d-bd68-c36072c3da0d"
|
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},
|
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"typeVersion": 1
|
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},
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{
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|
"id": "416a09d5-c327-410d-b951-a2d08402c6fe",
|
|
"name": "Sticky Note1",
|
|
"type": "n8n-nodes-base.stickyNote",
|
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"position": [
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180,
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-120
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],
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"parameters": {
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"color": 7,
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"width": 820,
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"height": 720,
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"content": "## 2. Keep Secure by Preventing Raw SQL Statements\n[Read more about the PostgreSQL Node](https://docs.n8n.io/integrations/builtin/app-nodes/n8n-nodes-base.postgres/)\n\nWhilst it may be easier to just let the Agent provide the full raw SQL statement,\nit may expose you or your organisation to a real security risk where in the worst\ncase, data may be unknowingly leaked or deleted.\n\nForcing the agent to provide only the parameters of the query\nmeans we can guard somewhat against this risk and also allows\nuse of query parameters as best practice against SQL injection attacks.\n"
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},
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"typeVersion": 1
|
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},
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{
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"id": "0187fb3f-4c31-461d-84e9-4a4a0bf4188d",
|
|
"name": "Sticky Note2",
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"type": "n8n-nodes-base.stickyNote",
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"position": [
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-1000,
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-560
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|
],
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"parameters": {
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"width": 440,
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"height": 1320,
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"content": "## Try It Out!\n### This n8n demonstrates how to build a simple PostgreSQL MCP server to manage your PostgreSQL database such as HR, Payroll, Sale, Inventory and More!\n\nThis MCP example is based off an official MCP reference implementation which can be found here -https://github.com/modelcontextprotocol/servers/tree/main/src/postgres\n\n### How it works\n* A MCP server trigger is used and connected to 5 tools: 2 postgreSQL and 3 custom workflow.\n* The 2 postgreSQL tools are simple read-only queries and as such, the postgreSQL tool can be simply used.\n* The 3 custom workflow tools are used for select, insert and update queries as these are operations which require a bit more discretion.\n* Whilst it may be easier to allow the agent to use raw SQL queries, we may find it a little safer to just allow for the parameters instead. The custom workflow tool allows us to define this restricted schema for tool input which we'll use to construct the SQL statement ourselves.\n* All 3 custom workflow tools trigger the same \"Execute workflow\" trigger in this very template which has a switch to route the operation to the correct handler.\n* Finally, we use our standard PostgreSQL node to handle select, insert and update operations. The responses are then sent back to the the MCP client.\n\n### How to use\n* This PostgreSQL MCP server allows any compatible MCP client to manage a PostgreSQL database by supporting select, create and update operations. You will need to have a database available before you can use this server.\n* Connect your MCP client by following the n8n guidelines here - https://docs.n8n.io/integrations/builtin/core-nodes/n8n-nodes-langchain.mcptrigger/#integrating-with-claude-desktop\n* Try the following queries in your MCP client:\n * \"Please help me check if Alex has an entry in the users table. If not, please help me create a record for her.\"\n * \"What was the top selling product in the last week?\"\n * \"How many high priority support tickets are still open this morning?\"\n\n### Requirements\n* PostgreSQL for database. This can be an external database such as Supabase or one you can host internally.\n* MCP Client or Agent for usage such as Claude Desktop - https://claude.ai/download\n\n### Customising this workflow\n* If the scope of schemas or tables is too open, try restrict it so the MCP serves a specific purpose for business operations. eg. Confine the querying and editing to HR only tables before providing access to people in that department.\n* Remember to set the MCP server to require credentials before going to production and sharing this MCP server with others!"
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},
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"typeVersion": 1
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},
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{
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"id": "bc4e427f-f6fd-4243-844a-8edf2dc1a0e9",
|
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"name": "Sticky Note3",
|
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"type": "n8n-nodes-base.stickyNote",
|
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"position": [
|
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-520,
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-240
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],
|
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"parameters": {
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"color": 5,
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"width": 380,
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"height": 100,
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"content": "### Always Authenticate Your Server!\nBefore going to production, it's always advised to enable authentication on your MCP server trigger."
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},
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"typeVersion": 1
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}
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],
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"pinData": {},
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"connections": {
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"Operation": {
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"main": [
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[
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{
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"node": "ReadTableRecord",
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"type": "main",
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"index": 0
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}
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],
|
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[
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{
|
|
"node": "CreateTableRecord",
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"type": "main",
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"index": 0
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}
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],
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[
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{
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|
"node": "UpdateTableRecord",
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"type": "main",
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"index": 0
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}
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]
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]
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},
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"ListTables": {
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"ai_tool": [
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[
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{
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"node": "PostgreSQL MCP Server",
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"type": "ai_tool",
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"index": 0
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}
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]
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]
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},
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"ReadTableRows": {
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"ai_tool": [
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[
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{
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"node": "PostgreSQL MCP Server",
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"type": "ai_tool",
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"index": 0
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}
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]
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]
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},
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"GetTableSchema": {
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"ai_tool": [
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[
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{
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"node": "PostgreSQL MCP Server",
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"type": "ai_tool",
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"index": 0
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}
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]
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]
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},
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"ReadTableRecord": {
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"main": [
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[]
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},
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"CreateTableRecords": {
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"ai_tool": [
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[
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{
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"node": "PostgreSQL MCP Server",
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"type": "ai_tool",
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"index": 0
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]
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]
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},
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"UpdateTableRecords": {
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"ai_tool": [
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[
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{
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"node": "PostgreSQL MCP Server",
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"type": "ai_tool",
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"index": 0
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]
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},
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"When Executed by Another Workflow": {
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"main": [
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[
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{
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"node": "Operation",
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"type": "main",
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"index": 0
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}
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]
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]
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}
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}
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} |