MySQL 或 MariaDB 查询所有数据库名下表格名、表格注释、字段名、字段类型、字段注释

1. 查询所有数据库名下所有表名、表注释和所有字段名、数据类型、字段注释

SELECT
    t.TABLE_SCHEMA AS 库名,
    t.TABLE_NAME AS 表名,
    t.TABLE_COMMENT AS 表注释,
    c.COLUMN_NAME AS 字段名,
    c.COLUMN_TYPE AS 数据类型,
    c.COLUMN_COMMENT AS 字段注释
FROM
    INFORMATION_SCHEMA.TABLES AS t,
    INFORMATION_SCHEMA.COLUMNS AS c
WHERE
    c.TABLE_NAME = t.TABLE_NAME
    AND t.TABLE_SCHEMA = 'schema_name';

2. 查询数据库名下所有表名、表注释

SELECT
    TABLE_NAME AS 表名,
    TABLE_COMMENT AS 表注释
FROM
    INFORMATION_SCHEMA.TABLES
WHERE
    TABLE_SCHEMA = 'schema_name';

3. 查询数据库名下某个表格名下所有字段名、数据类型、字段注释

SELECT
    COLUMN_NAME AS 字段名,
    DATA_TYPE AS 数据类型,
    COLUMN_COMMENT AS 字段注释
FROM
    INFORMATION_SCHEMA.COLUMNS
WHERE
    TABLE_SCHEMA = 'schema_name'
    AND TABLE_NAME = 'table_name';

4. 查询数据库下所有表下所有字段名、数据类型、字段注释

SELECT
    COLUMN_NAME AS 字段名,
    DATA_TYPE AS 数据类型,
    COLUMN_COMMENT AS 字段注释
FROM
    INFORMATION_SCHEMA.COLUMNS
WHERE
    TABLE_SCHEMA = 'schema_name';

5. 查询数据库下所有表名、表注释和所有字段名、数据类型、字段注释

SELECT
    t.TABLE_NAME AS 表名,
    t.TABLE_COMMENT AS 表注释,
    c.COLUMN_NAME AS 字段名,
    c.COLUMN_TYPE AS 数据类型,
    c.COLUMN_COMMENT AS 字段注释
FROM
    INFORMATION_SCHEMA.TABLES AS t,
    INFORMATION_SCHEMA.COLUMNS AS c
WHERE
    c.TABLE_NAME = t.TABLE_NAME
    AND t.TABLE_SCHEMA = 'schema_name';