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SHOW-FUNCTIONS

SHOW-FUNCTIONS

Name

SHOW FUNCTIONS

Description

查看数据库下所有的自定义(系统提供)的函数。如果用户指定了数据库,那么查看对应数据库的,否则直接查询当前会话所在数据库

需要对这个数据库拥有 SHOW 权限

语法

SHOW [FULL] [BUILTIN] FUNCTIONS [IN|FROM db] [LIKE 'function_pattern']

Parameters

full:表示显示函数的详细信息 builtin:表示显示系统提供的函数 db: 要查询的数据库名字 function_pattern: 用来过滤函数名称的参数

语法

SHOW GLOBAL [FULL] FUNCTIONS [LIKE 'function_pattern']

Parameters

global:表示要展示的是全局函数 full:表示显示函数的详细信息 function_pattern: 用来过滤函数名称的参数

注意: "global"关键字在v2.0版本及以后才可用

Example

mysql> show full functions in testDb\G
*************************** 1. row ***************************
Signature: my_add(INT,INT)
Return Type: INT
Function Type: Scalar
Intermediate Type: NULL
Properties: {"symbol":"_ZN9doris_udf6AddUdfEPNS_15FunctionContextERKNS_6IntValES4_","object_file":"http://host:port/libudfsample.so","md5":"cfe7a362d10f3aaf6c49974ee0f1f878"}
*************************** 2. row ***************************
Signature: my_count(BIGINT)
Return Type: BIGINT
Function Type: Aggregate
Intermediate Type: NULL
Properties: {"object_file":"http://host:port/libudasample.so","finalize_fn":"_ZN9doris_udf13CountFinalizeEPNS_15FunctionContextERKNS_9BigIntValE","init_fn":"_ZN9doris_udf9CountInitEPNS_15FunctionContextEPNS_9BigIntValE","merge_fn":"_ZN9doris_udf10CountMergeEPNS_15FunctionContextERKNS_9BigIntValEPS2_","md5":"37d185f80f95569e2676da3d5b5b9d2f","update_fn":"_ZN9doris_udf11CountUpdateEPNS_15FunctionContextERKNS_6IntValEPNS_9BigIntValE"}
*************************** 3. row ***************************
Signature: id_masking(BIGINT)
Return Type: VARCHAR
Function Type: Alias
Intermediate Type: NULL
Properties: {"parameter":"id","origin_function":"concat(left(`id`, 3), `****`, right(`id`, 4))"}

3 rows in set (0.00 sec)
mysql> show builtin functions in testDb like 'year%';
+---------------+
| Function Name |
+---------------+
| year |
| years_add |
| years_diff |
| years_sub |
+---------------+
2 rows in set (0.00 sec)

mysql> show global full functions\G;
*************************** 1. row ***************************
Signature: decimal(ALL, INT, INT)
Return Type: VARCHAR
Function Type: Alias
Intermediate Type: NULL
Properties: {"parameter":"col, precision, scale","origin_function":"CAST(`col` AS decimal(`precision`, `scale`))"}
*************************** 2. row ***************************
Signature: id_masking(BIGINT)
Return Type: VARCHAR
Function Type: Alias
Intermediate Type: NULL
Properties: {"parameter":"id","origin_function":"concat(left(`id`, 3), `****`, right(`id`, 4))"}
2 rows in set (0.00 sec)

mysql> show global functions ;
+---------------+
| Function Name |
+---------------+
| decimal |
| id_masking |
+---------------+
2 rows in set (0.00 sec)

Keywords

SHOW, FUNCTIONS

Best Practice