Previously, and in all versions of MySQL, no warnings are triggered since they did erroneously behave as a number: SELECT CAST ( 0 xAA AS UNSIGNED ), CAST ( x 'aa' AS UNSIGNED ), CAST ( X 'aa' AS UNSIGNED ) + -+-+-+ | CAST ( 0 xAA AS UNSIGNED ) | CAST ( x 'aa' AS UNSIGNED ) | CAST ( X 'aa' AS UNSIGNED ) | + -+-+-+ | 170 | 0 | 0 | + -+-+-+ 1 row in set, 2 warnings ( 0. Using CAST() to order an ENUM field as a CHAR rather than the internal numerical value: CREATE TABLE enum_list ( enum_field enum ( 'c', 'a', 'b' )) INSERT INTO enum_list ( enum_field ) VALUES ( 'c' ),( 'a' ),( 'c' ),( 'b' ) SELECT * FROM enum_list ORDER BY enum_field + -+ | enum_field | + -+ | c | | c | | a | | b | + -+ SELECT * FROM enum_list ORDER BY CAST ( enum_field AS CHAR ) + -+ | enum_field | + -+ | a | | b | | c | | c | + -+įrom MariaDB 5.5.31, the following will trigger warnings, since x'aa' and 'X'aa' no longer behave as a number. The NUMERIC type can hold a value up to 131,072. For example, the number 1234.567 has the precision 7 and scale 3. In this syntax, the precision is the total number of digits and the scale is the number of digits in the fraction part. If you also want to change the collation, you have to use the COLLATE operator: SELECT COLLATION ( CAST ( 123 AS CHAR CHARACTER SET utf8 ) COLLATE utf8_unicode_ci ) + -+ | COLLATION ( CAST ( 123 AS CHAR CHARACTER SET utf8 ) COLLATE utf8_unicode_ci ) | + -+ | utf8_unicode_ci | + -+ Typically, you use the NUMERIC type for numbers that require exactness such as monetary amounts or quantities. SELECT COLLATION ( CAST ( 123 AS CHAR )) + -+ | COLLATION ( CAST ( 123 AS CHAR )) | + -+ | latin1_swedish_ci | + -+ SELECT COLLATION ( CAST ( 123 AS CHAR CHARACTER SET utf8 )) + -+ | COLLATION ( CAST ( 123 AS CHAR CHARACTER SET utf8 )) | + -+ | utf8_general_ci | + -+ When used with CHAR CHARACTER SET, the default collation for that character set will be used. Note that when one casts to CHAR without specifying the character set, the collation_connection character set collation will be used. Simple casts: SELECT CAST ( "abc" AS BINARY ) SELECT CAST ( "1" AS UNSIGNED INTEGER ) SELECT CAST ( 123 AS CHAR CHARACTER SET utf8 ) This introduced an incompatibility with previous versions of MariaDB, and all versions of MySQL (see the example below). In 5.5.31 it was intentionally changed to behave as a string in all contexts (and never as a number). Until MariaDB 5.5.31, X'HHHH', the standard SQL syntax for binary string literals, erroneously worked in the same way as 0xHHHH. The syntax of the CAST operator’s another version is as follows as well: Syntax. The target data type is the data type to which the expression will get converted. In MariaDB 10.4 and later, you can use the CAST() function with the INTERVAL keyword. How does the CAST Operator work in PostgreSQL The cast operator converts one data type to another, where the table column or an expression’s data type is decided to be. The main difference between CAST and CONVERT() is that CONVERT(expr,type) is ODBC syntax while CAST(expr as type) and CONVERT(. VARCHAR (in Oracle mode, from MariaDB 10.3).The type can be one of the following values: The CAST() function takes a value of one type and produces a value of another type, similar to the CONVERT() function.
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