add bugfix for SQLDBChain

packages/components/nodes/chains/SqlDatabaseChain/SqlDatabaseChain.ts

@@ -1,5 +1,5 @@
 import { INode, INodeData, INodeParams } from '../../../src/Interface'
-import { SqlDatabaseChain } from 'langchain/chains'
+import { SqlDatabaseChain, SqlDatabaseChainInput } from 'langchain/chains'
 import { getBaseClasses } from '../../../src/utils'
 import { DataSource } from 'typeorm'
 import { SqlDatabase } from 'langchain/sql_db'
@@ -51,31 +51,42 @@ class SqlDatabaseChain_Chains implements INode {
     }
 
     async init(nodeData: INodeData): Promise<any> {
-        const databaseType = nodeData.inputs?.database
+        const databaseType = nodeData.inputs?.database as 'sqlite'
         const llm = nodeData.inputs?.llm as BaseLLM
         const dbFilePath = nodeData.inputs?.dbFilePath
 
-        const datasource = new DataSource({
+        const chain = await getSQLDBChain(databaseType, dbFilePath, llm)
-            type: databaseType,
-            database: dbFilePath
-        })
-
-        const db = await SqlDatabase.fromDataSourceParams({
-            appDataSource: datasource
-        })
-
-        const chain = new SqlDatabaseChain({
-            llm,
-            database: db
-        })
         return chain
     }
 
     async run(nodeData: INodeData, input: string): Promise<string> {
-        const chain = nodeData.instance as SqlDatabaseChain
+        const databaseType = nodeData.inputs?.database as 'sqlite'
+        const llm = nodeData.inputs?.llm as BaseLLM
+        const dbFilePath = nodeData.inputs?.dbFilePath
+
+        const chain = await getSQLDBChain(databaseType, dbFilePath, llm)
         const res = await chain.run(input)
         return res
     }
 }
 
+const getSQLDBChain = async (databaseType: 'sqlite', dbFilePath: string, llm: BaseLLM) => {
+    const datasource = new DataSource({
+        type: databaseType,
+        database: dbFilePath
+    })
+
+    const db = await SqlDatabase.fromDataSourceParams({
+        appDataSource: datasource
+    })
+
+    const obj: SqlDatabaseChainInput = {
+        llm,
+        database: db
+    }
+
+    const chain = new SqlDatabaseChain(obj)
+    return chain
+}
+
 module.exports = { nodeClass: SqlDatabaseChain_Chains }