如何为 Azure SQL 上的弹性查询设置 CONNECTION_OPTIONS = 'ApplicationIntent=ReadOnly'？

Question

I am accessing the other database using elastic queries. The data source was created like this:

CREATE EXTERNAL DATA SOURCE TheCompanyQueryDataSrc WITH (
    TYPE = RDBMS,
    --CONNECTION_OPTIONS = 'ApplicationIntent=ReadOnly',
    CREDENTIAL = ElasticDBQueryCred,
    LOCATION = 'thecompanysql.database.windows.net',
    DATABASE_NAME = 'TheCompanyProd'
);

To reduce the database load, the read-only replica was created and should be used. As far as I understand it, I should add the CONNECTION_OPTIONS = 'ApplicationIntent=ReadOnly' (commented out in the above code). However, I get only the Incorrect syntax near 'CONNECTION_OPTIONS'

Both databases (the one that sets the connection + external tables, and the other to-be-read-only are at the same server (thecompanysql.database.windows.net). Both are set the compatibility lever SQL Server 2019 (150).

What else should I set to make it work?

Answer 1

The CREATE EXTERNAL DATA SOURCE Syntax doesn't support the option CONNECTION_OPTIONS = 'ApplicationIntent=ReadOnly' . We can't use that in the statements.

If you want achieve that readonly request, the way is that please use the user account which only has the readonly(db_reader) permission to login the external database.

For example:

CREATE MASTER KEY ENCRYPTION BY PASSWORD = '<password>' ;

CREATE DATABASE SCOPED CREDENTIAL SQL_Credential
WITH
  IDENTITY = '<username>' -- readonly user account,
  SECRET = '<password>' ;

CREATE EXTERNAL DATA SOURCE MyElasticDBQueryDataSrc
WITH
  ( TYPE = RDBMS ,
    LOCATION = '<server_name>.database.windows.net' ,
    DATABASE_NAME = 'Customers' ,
    CREDENTIAL = SQL_Credential
  ) ;

Since the option is not supported, then we can't use it with elastic query. The only way to connect to the Azure SQL data with SSMS is like this:

HTH.