函数相关操作

• 建立函数。

postgres=# CREATE OR REPLACE FUNCTION tbase_f1(a_1 text) returns text as
postgres-# $$
postgres$# begin
postgres$#     return a_1;
postgres$# end;
postgres$# $$
postgres-# language plpgsql; 
CREATE FUNCTION
postgres=# CREATE OR REPLACE FUNCTION pgxc.tbase_f2(a_2 text) returns text as
postgres-# $$
postgres$# begin
postgres$#     return a_2;
postgres$# end;
postgres$# $$
postgres-# language plpgsql; 
CREATE FUNCTION
postgres=# 

• \df查看函数列表。

postgres=# \df
                          List of functions
 Schema |  Name   | Result data type |Argument data types |  Type  
--------+----------+------------------+---------------------+--------
 pgxc   |tbase_f2 | text             | a_2 text            | normal
 public | tbase_f1 | text             | a_1 text            | normal
(2 rows)

• \df+查看函数列表详细信息（包含注释），定义。

postgres=# \x
Expanded display is on.
postgres=# \df+ tbase*
                          List of functions
-[ RECORD 1 ]-------+--------------------
Schema              | pgxc
Name                | tbase_f2
Result data type    | text
Argument data types | a_2 text
Type                | normal
Volatility          | volatile
Parallel            | unsafe
Owner               | tbase
Security            | invoker
Access privileges   | 
Language            | plpgsql
Source code         |                    +
                    |     begin          +
                   |      return a_2;   +
                    |     end;           +
                   | 
Description         | 
-[ RECORD 2 ]-------+--------------------
Schema              | public
Name                | tbase_f1
Result data type    | text
Argument data types | a_1 text
Type                | normal
Volatility          | volatile
Parallel            | unsafe
Owner               | tbase
Security            | invoker
Access privileges   | 
Language            | plpgsql
Source code         |                    +
                    |     begin          +
                    |         return a_1;+
                    |     end;           +
                   | 
Description         | 

• \df+函数名显示某个函数的详细信息。

postgres=# \df+ tbase_f1
                          List of functions
-[ RECORD 1 ]-------+--------------------
Schema              | public
Name                | tbase_f1
Result data type    | text
Argument data types | a_1 text
Type                | normal
Volatility          | volatile
Parallel            | unsafe
Owner               | tbase
Security            | invoker
Access privileges   | 
Language            | plpgsql
Source code         |                    +
                    |     begin          +
                    |         return a_1;+
                    |     end;           +
                   | 
Description         | 

• \df+通配符列出适配的函数。

postgres=# \df+ tbase*
                          List of functions
-[ RECORD 1 ]-------+--------------------
Schema              | pgxc
Name                | tbase_f2
Result data type    | text
Argument data types | a_2 text
Type                | normal
Volatility          | volatile
Parallel            | unsafe
Owner               | tbase
Security            | invoker
Access privileges   | 
Language            | plpgsql
Source code         |                    +
                    |     begin          +
                   |      return a_2;   +
                    |     end;           +
                   | 
Description         | 
-[ RECORD 2 ]-------+--------------------
Schema              | public
Name                | tbase_f1
Result data type    | text
Argument data types | a_1 text
Type                | normal
Volatility          | volatile
Parallel            | unsafe
Owner               | tbase
Security            | invoker
Access privileges   | 
Language            | plpgsql
Source code         |                    +
                    |     begin          +
                    |         return a_1;+
                    |     end;           +
                   | 
Description         | 

postgres=# \df+ *f1   
                          List of functions
-[ RECORD 1 ]-------+--------------------
Schema              | public
Name                | tbase_f1
Result data type    | text
Argument data types | a_1 text
Type                | normal
Volatility          | volatile
Parallel            | unsafe
Owner               | tbase
Security            | invoker
Access privileges   | 
Language            | plpgsql
Source code         |                    +
                    |     begin          +
                    |         return a_1;+
                    |     end;           +
                   | 
Description