Information functions are used to retrieve dynamic database information. This topic describes the information functions that are supported or not supported by PolarDB-X 1.0.

Supported functions

PolarDB-X 1.0 supports the following information functions.

Function Description
CONNECTION_ID() Return the connection ID (thread ID) for the connection
CURRENT_USER(), CURRENT_USER The authenticated user name and host name
DATABASE() Return the default (current) database name
LAST_INSERT_ID() Value of the AUTOINCREMENT column for the last INSERT
SCHEMA() Synonym for DATABASE()
SESSION_USER() Synonym for USER()
SYSTEM_USER() Synonym for USER()
USER() The user name and host name provided by the client
VERSION() Return a string that indicates the MySQL server version

Functions that are not supported

PolarDB-X 1.0 does not support the following information functions that are supported by MySQL 5.7.

Function Description
BENCHMARK() Repeatedly execute an expression
CHARSET() Return the character set of the argument
COERCIBILITY() Return the collation coercibility value of the string argument
COLLATION() Return the collation of the string argument
FOUND_ROWS() For a SELECT with a LIMIT clause, the number of rows that would be returned were there no LIMIT clause
ROW_COUNT() The number of rows updated