达梦数据库常用sql查询
达梦数据库是一款高性能的商用关系型数据库,以下是一些常见的SQL查询示例:
- 查询表中所有数据:
SELECT * FROM table_name;
- 查询表中特定列的数据:
SELECT column1, column2 FROM table_name;
- 带条件的查询:
SELECT * FROM table_name WHERE condition;
- 排序查询结果:
SELECT * FROM table_name ORDER BY column ASC|DESC;
- 计算行数:
SELECT COUNT(*) FROM table_name;
- 查询去重复的数据:
SELECT DISTINCT column_name FROM table_name;
- 分页查询:
SELECT * FROM table_name LIMIT offset, row_count;
- 创建表:
CREATE TABLE table_name (
column1 datatype,
column2 datatype,
...
);
- 插入数据:
INSERT INTO table_name (column1, column2) VALUES (value1, value2);
- 更新数据:
UPDATE table_name SET column1 = value1 WHERE condition;
- 删除数据:
DELETE FROM table_name WHERE condition;
- 创建索引:
CREATE INDEX index_name ON table_name (column_name);
- 结合子查询:
SELECT * FROM table_name WHERE column1 IN (SELECT column FROM another_table);
- 连接查询:
SELECT * FROM table1 JOIN table2 ON table1.column_id = table2.column_id;
- 创建视图:
CREATE VIEW view_name AS SELECT * FROM table_name WHERE condition;
这些是达梦数据库中常用的SQL查询操作,具体使用时需要根据实际的表结构和查询需求进行调整。
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