查看数据

使用系统表pg_tables查询数据库所有表的信息。
```
postgres=# SELECT * FROM pg_tables;
```
使用gsql的\d+命令查询表的属性。
```
postgres=# \d+ customer_t1;
```
执行如下命令查询表customer_t1****的数据量。
```
postgres=# SELECT count(*) FROM customer_t1;
```
执行如下命令查询表customer_t1的所有数据。
```
postgres=# SELECT * FROM customer_t1;
```
执行如下命令只查询字段c_customer_sk的数据。
```
postgres=# SELECT c_customer_sk FROM customer_t1;
```

执行如下命令过滤字段c_customer_sk的重复数据。

postgres=# SELECT DISTINCT( c_customer_sk ) FROM customer_t1;

执行如下命令查询字段c_customer_sk为3869的所有数据。

postgres=# SELECT * FROM customer_t1 WHERE c_customer_sk = 3869;

执行如下命令按照字段c_customer_sk进行排序。

postgres=# SELECT * FROM customer_t1 ORDER BY c_customer_sk;