B.2 Types of Error Values

When an error occurs in MySQL, the server returns two types of error values:

  • A MySQL-specific error code. This value is numeric. It is not portable to other database systems.

  • An SQLSTATE value. The value is a five-character string (for example, '42S02'). The values are taken from ANSI SQL and ODBC and are more standardized.

A message string that provides a textual description of the error is also available.

When an error occurs, the MySQL error code, SQLSTATE value, and message string are available using C API functions:

For prepared statements, the corresponding error functions are mysql_stmt_errno(), mysql_stmt_sqlstate(), and mysql_stmt_error(). All error functions are described in Section 20.6, “MySQL C API”.

The number of errors, warnings, and notes for the previous statement can be obtained by calling mysql_warning_count(). See Section, “mysql_warning_count()”.

The first two characters of an SQLSTATE value indicate the error class:

  • Class = '00' indicates success.

  • Class = '01' indicates a warning.

  • Class = '02' indicates not found. This is relevant within the context of cursors and is used to control what happens when a cursor reaches the end of a data set. This condition also occurs for SELECT ... INTO var_list statements that retrieve no rows.

  • Class > '02' indicates an exception.

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