mysql如何查询所有表和字段信息

SELECT * FROM information_schema.`TABLES` WHERE TABLE_SCHEMA = 'erp';

SELECT TABLE_NAME, TABLE_COMMENT FROM information_schema.`TABLES` WHERE TABLE_SCHEMA = 'erp';

SELECT TABLE_SCHEMA AS '库名', TABLE_NAME AS '表名', COLUMN_NAME AS '列名', ORDINAL_POSITION AS '列的排列顺序', COLUMN_DEFAULT AS '默认值', IS_NULLABLE AS '是否为空', DATA_TYPE AS '数据类型', CHARACTER_MAXIMUM_LENGTH AS '字符最大长度', NUMERIC_PRECISION AS '数值精度(最大位数)', NUMERIC_SCALE AS '小数精度', COLUMN_TYPE AS 列类型, COLUMN_KEY 'KEY', EXTRA AS '额外说明', COLUMN_COMMENT AS '注释' FROM information_schema.`COLUMNS` WHERE TABLE_SCHEMA = 'erp' ORDER BY TABLE_NAME, ORDINAL_POSITION;

SELECT C.TABLE_SCHEMA AS '库名', T.TABLE_NAME AS '表名', T.TABLE_COMMENT AS '表注释', C.COLUMN_NAME AS '列名', C.COLUMN_COMMENT AS '列注释', C.ORDINAL_POSITION AS '列的排列顺序', C.COLUMN_DEFAULT AS '默认值', C.IS_NULLABLE AS '是否为空', C.DATA_TYPE AS '数据类型', C.CHARACTER_MAXIMUM_LENGTH AS '字符最大长度', C.NUMERIC_PRECISION AS '数值精度(最大位数)', C.NUMERIC_SCALE AS '小数精度', C.COLUMN_TYPE AS 列类型, C.COLUMN_KEY 'KEY', C.EXTRA AS '额外说明' FROM information_schema.`TABLES` T LEFT JOIN information_schema.`COLUMNS` C ON T.TABLE_NAME = C.TABLE_NAME AND T.TABLE_SCHEMA = C.TABLE_SCHEMA WHERE T.TABLE_SCHEMA = 'erp' ORDER BY C.TABLE_NAME, C.ORDINAL_POSITION;