Information functions-PolarDB(PolarDB)-阿里云帮助中心

Information functions return dynamic database information such as the current user, connection ID, and database version. PolarDB-X supports most standard MySQL information functions, with one exception noted below.

Supported functions

PolarDB-X supports the following information functions.

Function	Description
`CONNECTION_ID()`	Returns the unique ID of the current connection.
`CURRENT_USER()`, `CURRENT_USER`	Returns the details of the user who calls the function.
`DATABASE()`	Returns the name of the current database.
`LAST_INSERT_ID()`	Returns the value generated for an auto-increment primary key by the most recent `INSERT` statement.
`SCHEMA()`	Returns the name of the current database. Equivalent to `DATABASE()`.
`SESSION_USER()`	Returns the details of the user who calls the function. Equivalent to `USER()`.
`SYSTEM_USER()`	Returns the details of the user who calls the function. Equivalent to `USER()`.
`USER()`	Returns the details of the user who calls the function.
`VERSION()`	Returns the database version string.
`BENCHMARK()`	Executes an expression repeatedly for performance testing.
`CHARSET()`	Returns the character set name of a string argument.
`COLLATION()`	Returns the collation of a string argument.
`FOUND_ROWS()`	Returns the number of rows in the result set by the last SQL statement.
`ROW_COUNT()`	Returns the number of rows that are affected by the last SQL statement.

Unsupported functions

The following information function is not supported by PolarDB-X. It is available in MySQL 5.7.

Function	Description
`COERCIBILITY()`	Returns the collation coercibility value of a string argument.