sql data migration verification script (#1049)

Co-authored-by: midhun-aot <105463561+midhun-aot@users.noreply.github.com>

Author: nikhila-aot

migration_verification/.gitignore

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+# compiled output
+/dist
+/node_modules
+/build
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local

migration_verification/README.md

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+## Introduction
+
+This code can be used to verify the count of records in each table once the data is migrated from SQL Server to Postgres.
+
+
+## How to run
+
+### Usage:
+
+Please make sure the source and destination connection string are updated in the .env before running the script.
+
+Run the script from the command prompt with:
+
+```
+npx ts-node compareData.ts
+
+```

migration_verification/compareData.ts

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+import * as dotenv from 'dotenv';
+dotenv.config();
+import * as sql from 'mssql';
+import type { config } from 'mssql';
+const { Client } = require('pg');
+
+// --- SQL Server (NTLM) Config ---
+const sqlServerConfig: config = {
+    server: process.env.SQL_SERVER || 'localhost',
+    database: process.env.SQL_DB,
+    port: Number(process.env.SQL_PORT),
+    user: process.env.SQL_USER,                  // NTLM user
+    password: process.env.SQL_PASSWORD,   // NTLM password
+    domain: process.env.SQL_DOMAIN,                 // important for NTLM
+    options: {
+        encrypt: false,
+        trustServerCertificate: true,
+        enableArithAbort: true,
+    }
+};
+
+// --- PostgreSQL Config ---
+const pgClient = new Client({
+    user: process.env.PG_USER,
+    host: process.env.PG_HOST || 'localhost',
+    database: process.env.PG_DB,
+    password: process.env.PG_PASSWORD,
+    port: Number(process.env.PG_PORT) || 5432,
+});
+
+// --- Helper: PascalCase → snake_case ---
+function toSnakeCase(str: string): string {
+    return str
+        .replace(/([a-z0-9])([A-Z])/g, '$1_$2')
+        .replace(/([A-Z])([A-Z][a-z])/g, '$1_$2')
+        .toLowerCase();
+}
+
+async function testConnection() {
+    try {
+        const pool = await sql.connect(sqlServerConfig);
+        const result = await pool.request().query('SELECT GETDATE() AS now');
+        console.log('Connected! Current time:', result.recordset[0].now);
+        await pool.close();
+    } catch (err) {
+        console.error('Connection failed:', err);
+    }
+}
+
+async function compareAllTableRowCounts(): Promise<void> {
+    const pool = new sql.ConnectionPool(sqlServerConfig);
+    try {
+        await pool.connect();
+        await pgClient.connect();
+
+        // Get all SQL Server table names
+        const tableQuery = `
+      SELECT TABLE_NAME
+      FROM INFORMATION_SCHEMA.TABLES
+      WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_SCHEMA = 'dbo'
+    `;
+
+        const result = await pool.request().query(tableQuery);
+        const tableNames: string[] = result.recordset.map((row: any) => row.TABLE_NAME);
+
+        //console.log('tableNames', tableNames);
+        console.log(`\n${'SQL Table'.padEnd(30)} ${'Postgres Table'.padEnd(30)} SQL Count  PG Count   Match`);
+        console.log('-'.repeat(85));
+
+        let pgTableNotFound = [];
+        let sqlTableNotFound = [];
+        for (const sqlTable of tableNames) {
+            const pgTable = toSnakeCase(sqlTable);
+            let sqlCount;
+            let pgCount;
+            //console.log('pgTable', pgTable);
+            try {
+                const sqlRes = await pool.request().query(`SELECT COUNT(*) AS count FROM [${sqlTable}]`);
+                sqlCount = Number(sqlRes.recordset[0].count);
+            } catch (e) {
+                sqlTableNotFound.push(pgTable);
+                //console.warn(`Could not query SQL Server table: ${sqlTable}`);
+            }
+
+            try {
+                const pgRes = await pgClient.query(`SELECT COUNT(*) FROM cats."${pgTable}"`);
+                pgCount = Number(pgRes.rows[0].count);
+            } catch (e) {
+                pgTableNotFound.push(pgTable);
+                //console.warn(`Could not query Postgres table: ${pgTable}`);
+            }
+
+
+            const match = sqlCount === pgCount ? '✅' : '❌';
+            //if (sqlCount !== pgCount)
+            console.log(`${sqlTable.padEnd(30)} ${pgTable.padEnd(30)} ${String(sqlCount).padEnd(10)} ${String(pgCount).padEnd(10)} ${match}`);
+        }
+
+        if (sqlTableNotFound.length > 0) {
+            console.log('-'.repeat(85));
+            console.log('Table not in Oracle:');
+            console.log('-'.repeat(85));
+            sqlTableNotFound.forEach((table) => {
+                console.log(table);
+            });
+        }
+
+        if (pgTableNotFound.length > 0) {
+            console.log('-'.repeat(85));
+            console.log('Table not in Postgres:');
+            console.log('-'.repeat(85));
+            pgTableNotFound.forEach((table) => {
+                console.log(table);
+            });
+        }
+    } catch (err) {
+        console.error('🚨 Connection or query failed:', err);
+    } finally {
+        await pool.close();       // Close the SQL Server connection pool properly
+        await pgClient.end();     // Close Postgres client connection
+    }
+}
+
+
+compareAllTableRowCounts();