将CHAR替换为VARCHAR2 [英] Replace CHAR with VARCHAR2

问题描述

如何在模式中的所有表中替换 CHAR 和 VARCHAR2 ？

How can I replace CHAR with VARCHAR2 in all tables in a schema?

注意：我很满意一个返回 ALTER TABLE 语句的查询，所以我可以保存脚本并再次运行。

Note: I'm content with a query that returns the ALTER TABLE statements so I can save the script and run it again.

推荐答案

select 'ALTER TABLE "' || owner || '"."' || table_name
|| '" MODIFY ("' || column_name
|| '" VARCHAR2(' || data_length || '));'
from all_tab_columns tc
where data_type = 'CHAR'
and owner = :schemaname
and exists (
    select 1
    from all_tables t
    where tc.owner = t.owner
    and tc.table_name = t.table_name
);

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