获取MySQL中某个数据库下所有表建表语句的DDL

Posted 2022-04-09 robinson1988

本脚本可以获取mysql中某个数据库下所有表建表语句的DDL
注意：本脚本需在MySQL8.0以上版本运行
注意：本脚本不获取VIEW创建语句
注意：本脚本没有处理主键，外键等约束
注意：本脚本只处理非分区表，分区表请自己改写脚本
注意：如果你做数据迁移，想把MySQL数据库迁移到其他数据库，自己改写脚本

WITH tab AS
 (SELECT table_name FROM information_schema.TABLES WHERE table_schema = '数据库名' and table_type='BASE TABLE')
SELECT CASE
         WHEN id = -1 THEN
          concat('create table ', table_name)
         WHEN id = 0 THEN
          '('
         WHEN id = 1 AND max_id = 1 THEN
          concat(' ', column_name, ' ', column_type)
         WHEN id = 1 AND max_id <> 1 THEN
          concat(' ', column_name, ' ', column_type, ',')
         WHEN id >= 1 AND id < max_id THEN
          concat(' ', column_name, ' ', column_type, ',')
         WHEN id = max_id THEN
          concat(' ', column_name, ' ', column_type)
         WHEN id = 999 THEN
          ');'
       END create_table_ddl
  FROM (SELECT table_name,
               ordinal_position id,
               max(ordinal_position) over(PARTITION BY table_schema, table_name) max_id,
               column_name,
               concat(column_type,
                      CASE
                        WHEN is_nullable = 'NO' THEN
                         ' not null'
                        ELSE
                         ''
                      END,
                      CASE
                        WHEN COLUMN_DEFAULT IS NULL THEN
                         ''
                        WHEN COLUMN_DEFAULT IS NOT NULL AND
                             data_type IN ('varchar', 'char') THEN
                         concat(' default ', '''', column_default, '''')
                        WHEN COLUMN_DEFAULT IS NOT NULL AND
                             data_type NOT IN ('varchar', 'char') THEN
                         concat(' default ', column_default)
                      END,
                      '',
                      REPLACE(REPLACE(extra, 'DEFAULT_GENERATED', ''),
                              'auto_increment',
                              '')) column_type
          FROM information_schema.COLUMNS
         WHERE table_schema = '数据库名' and table_name in (select table_name from tab)
        UNION ALL
        SELECT table_name, -1 ordinal_position, NULL, NULL, NULL
          FROM tab
        UNION ALL
        SELECT table_name, 0 ordinal_position, NULL, NULL, NULL
          FROM tab
        UNION ALL
        SELECT table_name, 999 ordinal_position, NULL, NULL, NULL
          FROM tab
         ORDER BY table_name, id) a;

抓出当前账户下主键，外键，索引，视图，注释，check约束，函数，存储过程等等我就不贴了

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