Read all columns of all tables

Gets column metadata for all tables. This operation can be slow.

Standard SQL query example

This is the base query accepted by the connector. To execute it in SQL Server, you have to pass it to the Data Gateway via a Linked Server. See how to accomplish this using the examples below.

SELECT * FROM get_table_columns_admin WITH(TableName='*') --requires readonly permissions on sys_dictionary and sys_db_object tables

Using OPENQUERY in SQL Server

SELECT * FROM OPENQUERY([LS_TO_SERVICENOW_IN_GATEWAY], 'SELECT * FROM get_table_columns_admin WITH(TableName=''*'') --requires readonly permissions on sys_dictionary and sys_db_object tables')

Using EXEC in SQL Server (handling larger SQL text)

The major drawback of OPENQUERY is its inability to incorporate variables within SQL statements. This often leads to the use of cumbersome dynamic SQL (with numerous ticks and escape characters).

Fortunately, starting with SQL 2005 and onwards, you can utilize the EXEC (your_sql) AT [LS_TO_SERVICENOW_IN_GATEWAY] syntax.

DECLARE @MyQuery NVARCHAR(MAX) = 'SELECT * FROM get_table_columns_admin WITH(TableName=''*'') --requires readonly permissions on sys_dictionary and sys_db_object tables'
EXEC (@MyQuery) AT [LS_TO_SERVICENOW_IN_GATEWAY]