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[Feature] Support alias function (#6261)

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Implement #6260.

Add alias function type.
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qiye
2021-08-07 21:29:13 +08:00
committed by GitHub
parent 2f5b06ae70
commit 70825ce846
19 changed files with 761 additions and 66 deletions
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107
docs/en/sql-reference/sql-statements/Data Definition/create-function.md
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@ -25,50 +25,60 @@ under the License.
-->
# CREATE FUNCTION
##Description
## Description
### Syntax
```
CREATE [AGGREGATE] FUNCTION function_name
(angry type [...])
RETURNS ret_type
[INTERMEDIATE inter_type]
[PROPERTIES ("key" = "value" [, ...]) ]
CREATE [AGGREGATE] [ALIAS] FUNCTION function_name
(arg_type [, ...])
[RETURNS ret_type]
[INTERMEDIATE inter_type]
[WITH PARAMETER(param [,...]) AS origin_function]
[PROPERTIES ("key" = "value" [, ...]) ]
```
### Parameters
>`AGGREGATE`: If this is the case, it means that the created function is an aggregate function, otherwise it is a scalar function.
> `AGGREGATE`: If this is the case, it means that the created function is an aggregate function.
>
>`Function_name`: To create the name of the function, you can include the name of the database. For example: `db1.my_func'.
>
>` arg_type': The parameter type of the function is the same as the type defined at the time of table building. Variable-length parameters can be represented by `,...`. If it is a variable-length type, the type of the variable-length part of the parameters is the same as the last non-variable-length parameter type.
>
>`ret_type`: Function return type.
>
>`Inter_type`: A data type used to represent the intermediate stage of an aggregate function.
>
>`properties`: Used to set properties related to this function. Properties that can be set include
>
> "Object_file": Custom function dynamic library URL path, currently only supports HTTP/HTTPS protocol, this path needs to remain valid throughout the life cycle of the function. This option is mandatory
>
> "symbol": Function signature of scalar functions for finding function entries from dynamic libraries. This option is mandatory for scalar functions
>
> "init_fn": Initialization function signature of aggregate function. Necessary for aggregation functions
>
> "update_fn": Update function signature of aggregate function. Necessary for aggregation functions
>
> "merge_fn": Merge function signature of aggregate function. Necessary for aggregation functions
>
> "serialize_fn": Serialized function signature of aggregate function. For aggregation functions, it is optional, and if not specified, the default serialization function will be used
>
> "finalize_fn": A function signature that aggregates functions to obtain the final result. For aggregation functions, it is optional. If not specified, the default fetch result function will be used.
>
> "md5": The MD5 value of the function dynamic link library, which is used to verify that the downloaded content is correct. This option is optional
>
> "prepare_fn": Function signature of the prepare function for finding the entry from the dynamic library. This option is optional for custom functions
> `ALIAS`: If this is the case, it means that the created function is an alias function.
>
> "close_fn": Function signature of the close function for finding the entry from the dynamic library. This option is optional for custom functions
> If the above two items are not present, it means that the created function is a scalar function.
>
> `Function_name`: To create the name of the function, you can include the name of the database. For example: `db1.my_func'.
>
> `arg_type`: The parameter type of the function is the same as the type defined at the time of table building. Variable-length parameters can be represented by `,...`. If it is a variable-length type, the type of the variable-length part of the parameters is the same as the last non-variable-length parameter type.
> **NOTICE**: `ALIAS FUNCTION` variable-length parameters are not supported, and there is at least one parameter.
>
> `ret_type`: Required for creating a new function. This parameter is not required if you are aliasing an existing function.
>
> `inter_type`: A data type used to represent the intermediate stage of an aggregate function.
>
> `param`: The parameter used to represent the alias function, containing at least one.
>
> `origin_function`: Used to represent the original function corresponding to the alias function.
>
> `properties`: Used to set properties related to aggregate function and scalar function. Properties that can be set include
>
> "Object_file": Custom function dynamic library URL path, currently only supports HTTP/HTTPS protocol, this path needs to remain valid throughout the life cycle of the function. This option is mandatory
>
> "symbol": Function signature of scalar functions for finding function entries from dynamic libraries. This option is mandatory for scalar functions
>
> "init_fn": Initialization function signature of aggregate function. Necessary for aggregation functions
>
> "update_fn": Update function signature of aggregate function. Necessary for aggregation functions
>
> "merge_fn": Merge function signature of aggregate function. Necessary for aggregation functions
>
> "serialize_fn": Serialized function signature of aggregate function. For aggregation functions, it is optional, and if not specified, the default serialization function will be used
>
> "finalize_fn": A function signature that aggregates functions to obtain the final result. For aggregation functions, it is optional. If not specified, the default fetch result function will be used.
>
> "md5": The MD5 value of the function dynamic link library, which is used to verify that the downloaded content is correct. This option is optional
>
> "prepare_fn": Function signature of the prepare function for finding the entry from the dynamic library. This option is optional for custom functions
>
> "close_fn": Function signature of the close function for finding the entry from the dynamic library. This option is optional for custom functions
This statement creates a custom function. Executing this command requires that the user have `ADMIN` privileges.
@ -100,12 +110,29 @@ If the `function_name` contains the database name, the custom function will be c
```
CREATE AGGREGATE FUNCTION my_count (BIGINT) RETURNS BIGINT PROPERTIES (
"init_fn"= "_ZN9doris_udf6AddUdfEPNS_15FunctionContextERKNS_6IntValES4_",
"update_fn" = "zn9dorisudf11CountupdateepnsFunctionContexterknsIntvalepnsbigintvale",
"merge_fn" = "zn9dorisudf10CountMergeepnsFunctionContexterknsBigintvaleps2
"finalize_fn" = "zn9dorisudf13CountFinalizepnsFunctionContexterknsBigintvale",
"object_file" = "http://host:port/libudasample.so"
"init_fn"="_ZN9doris_udf9CountInitEPNS_15FunctionContextEPNS_9BigIntValE",
"update_fn"="_ZN9doris_udf11CountUpdateEPNS_15FunctionContextERKNS_6IntValEPNS_9BigIntValE",
"merge_fn"="_ZN9doris_udf10CountMergeEPNS_15FunctionContextERKNS_9BigIntValEPS2_",
"finalize_fn"="_ZN9doris_udf13CountFinalizeEPNS_15FunctionContextERKNS_9BigIntValE",
"object_file"="http://host:port/libudasample.so"
);
```
4. Create a scalar function with variable length parameters
```
CREATE FUNCTION strconcat(varchar, ...) RETURNS varchar properties (
"symbol" = "_ZN9doris_udf6StrConcatUdfEPNS_15FunctionContextERKNS_6IntValES4_",
"object_file" = "http://host:port/libmyStrConcat.so"
);
```
5. Create a custom alias function
```
CREATE ALIAS FUNCTION id_masking(INT) WITH PARAMETER(id)
AS CONCAT(LEFT(id, 3), '****', RIGHT(id, 4));
```
## keyword
CREATE,FUNCTION