USE information_schema;
SELECT
C.TABLE_NAME AS '表名' ,
T.TABLE_COMMENT AS '表中文名' ,
C.COLUMN_NAME AS '字段名' ,
C.COLUMN_COMMENT AS '字段中文名' ,
C.COLUMN_TYPE AS '数据类型' ,
C.EXTRA AS '主键'
FROM
COLUMNS C
INNER JOIN TABLES T ON C.TABLE_SCHEMA = T.TABLE_SCHEMA
AND C.TABLE_NAME = T.TABLE_NAME
WHERE
T.TABLE_SCHEMA = 'kanjia'
SELECT
t.TABLE_NAME AS 表名,
t.COLUMN_NAME AS 字段名,
t.COLUMN_TYPE AS 数据类型,
CASE IFNULL(t.COLUMN_DEFAULT,'Null')
WHEN '' THEN '空字符串'
WHEN 'Null' THEN 'NULL'
ELSE t.COLUMN_DEFAULT END AS 默认值,
CASE t.IS_NULLABLE WHEN 'YES' THEN '是' ELSE '否' END AS 是否允许为空,
t.COLUMN_COMMENT AS 字段说明
FROM information_schema.COLUMNS t
WHERE t.TABLE_SCHEMA = '数据库';
SELECT
TABLE_NAME AS '表名',
COLUMN_NAME AS '字段名',
COLUMN_TYPE AS '数据类型',
IS_NULLABLE AS '允许为空',
COLUMN_COMMENT AS '字段说明'
FROM
information_schema.`COLUMNS`
WHERE
TABLE_SCHEMA = 'boxuewz'
本文深入探讨了使用SQL从数据库中高效检索信息的方法,包括如何利用JOIN操作连接不同表,以及如何通过条件筛选获取特定数据。文章还展示了如何展示表结构和字段属性,如字段名、数据类型、默认值和是否允许为空等。
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