user_defined_field : sequence of characters in [a-zA-Z0-9_] class comparator : {== | != | <> | >= | => | <= | =< | < | >} value : { string_literal | integer_literal | float_literal | error_symbol | priority } count : integer_literal window_size : integer_literal string_literal : sequence of characters quoted as ’...’ or "..." integer_literal : sequence of characters in [0-9] class float_literal : integer_literal [. integer_literal ] error_symbol : valid MySQL error symbol such as ER_ACCESS_DENIED_ERROR or ER_STARTUP priority : { ERROR | WARNING | INFORMATION } 

Simple conditions compare a field to a value or test field existence. To construct more complex conditions, use the AND  and OR  operators. Both operators have the same precedence and evaluate left to right. 

To escape a character within a string, precede it by a backslash ( \ ). A backslash is required to include backslash itself or the string-quoting character, optional for other characters. 

For convenience, log_filter_dragnet  supports symbolic names for comparisons to certain fields. For readability and portability, symbolic values are preferable (where applicable) to numeric values. 

•Event priority values 1, 2, and 3 can be specified as ERROR , WARNING , and INFORMATION . Priority symbols are recognized only in comparisons with the prio  field. These comparisons are equivalent: 

IF prio == INFORMATION THEN ... IF prio == 3 THEN ... 

•Error codes can be specified in numeric form or as the corresponding error symbol. For example, ER_STARTUP  is the symbolic name for error 1408 , so these comparisons are equivalent: 

IF err_code == ER_STARTUP THEN ... IF err_code == 1408 THEN ... 

Error symbols are recognized only in comparisons with the err_code  field and user-defined fields. 

To find the error symbol corresponding to a given error code number, use one of these methods: 

•Check the list of server errors at Server Error Message Reference. 

•Use the perror  command. Given an error number argument, perror  displays information about the error, including its symbol. 

