查看对象

gsql工具提供了若干高级特性，便于用户使用。常见用法如下：

• 查看命令帮助信息

  \h [NAME]
  

  例如，查询ABORT的所有语法。

  openGauss=# \h ABORT
  Command:     ABORT
  Description: abort the current transaction
  Syntax:
  ABORT [ WORK | TRANSACTION ] ;
  

• 切换数据库

  \c dbname
  

  例如，将postgres数据库切换为数据库db_tpcc。

  openGauss=# \c db_tpcc
  Non-SSL connection (SSL connection is recommended when requiring high-security)
  You are now connected to database "db_tpcc" as user "omm".
  db_tpcc=# 
  

• 查询所有数据库

  \l
  

  示例如下。

  openGauss=# \l
                            List of databases
     Name    | Owner | Encoding  | Collate | Ctype | Access privileges
  -----------+-------+-----------+---------+-------+-------------------
   mydb      | omm   | GBK       | C       | C     |
   postgres  | omm   | SQL_ASCII | C       | C     |
   template0 | omm   | SQL_ASCII | C       | C     | =c/omm           +
             |       |           |         |       | omm=CTc/omm
   template1 | omm   | SQL_ASCII | C       | C     | =c/omm           +
             |       |           |         |       | omm=CTc/omm
  (4 rows)
  

• 查询当前数据库中的所有表

  \dt
  

  示例如下。

  openGauss=# \dt
                                List of relations
   Schema |      Name       | Type  | Owner |             Storage
  --------+-----------------+-------+-------+----------------------------------
   public | customer_t1     | table | omm   | {orientation=row,compression=no}
   public | customer_t1_bak | table | omm   | {orientation=row,compression=no}
  (2 rows)
  

• 查看表结构

  \d tablename
  

  例如，查看表customer_t1的表结构。

  openGauss=# \d customer_t1
          Table "public.customer_t1"
      Column     |     Type     | Modifiers
  ---------------+--------------+-----------
   c_customer_sk | integer      |
   c_customer_id | character(5) |
   c_first_name  | character(6) |
   c_last_name   | character(8) |
   amount        | integer      |