postgresql基本语法
时间: 2023-12-14 14:33:36 浏览: 50
以下是PostgreSQL基本语法的介绍:
1. 创建数据库:
```sql
CREATE DATABASE database_name;
```
2. 连接到数据库:
```sql
\c database_name;
```
3. 创建表格:
```sql
CREATE TABLE table_name (
column1 datatype1,
column2 datatype2,
column3 datatype3,
.....
);
```
4. 修改表格:
```sql
ALTER TABLE table_name ADD COLUMN column_name datatype;
ALTER TABLE table_name DROP COLUMN column_name;
ALTER TABLE table_name ALTER COLUMN column_name TYPE datatype;
```
5. 添加约束:
```sql
ALTER TABLE table_name ADD CONSTRAINT constraint_name UNIQUE (column1, column2, ...);
ALTER TABLE table_name ADD CONSTRAINT constraint_name PRIMARY KEY (column1, column2, ...);
ALTER TABLE table_name ADD CONSTRAINT constraint_name FOREIGN KEY (column1, column2, ...) REFERENCES other_table(column1, column2, ...);
```
6. 插入数据:
```sql
INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...);
```
7. 更新数据:
```sql
UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition;
```
8. 删除数据:
```sql
DELETE FROM table_name WHERE condition;
```
9. 查询数据:
```sql
SELECT column1, column2, ... FROM table_name WHERE condition ORDER BY column_name ASC/DESC;
```
10. 窗口函数:
```sql
SELECT column1, column2, ..., ROW_NUMBER() OVER (ORDER BY column_name ASC/DESC) FROM table_name WHERE condition;
```