Information Functions

TiDB supports most of the information functions available in MySQL 5.7.

TiDB supported MySQL functions

Name	Description
`BENCHMARK()`	Execute an expression in a loop
`CONNECTION_ID()`	Return the connection ID (thread ID) for the connection
`CURRENT_USER()`, `CURRENT_USER`	Return the authenticated user name and host name
`DATABASE()`	Return the default (current) database name
`FOUND_ROWS()`	For a `SELECT` with a `LIMIT` clause, the number of the rows that are returned if there is no `LIMIT` clause
`LAST_INSERT_ID()`	Return the value of the `AUTOINCREMENT` column for the last `INSERT`
`ROW_COUNT()`	The number of rows affected
`SCHEMA()`	Synonym for `DATABASE()`
`SESSION_USER()`	Synonym for `USER()`
`SYSTEM_USER()`	Synonym for `USER()`
`USER()`	Return the user name and host name provided by the client
`VERSION()`	Return a string that indicates the MySQL server version

TiDB specific functions

The following function is only supported by TiDB, and there is no equivalent function in MySQL.

Name	Description
`CURRENT_RESOURCE_GROUP()`	Return the name of the resource group that the current session is bound to

Unsupported functions

CHARSET()
COERCIBILITY()
COLLATION()