抓出Oralce當前賬戶下所有表建表語句，遷移到MySQL

有時候需要導出當前Oracle賬戶下所有的表結構信息，在其他Oracle測試庫重建，或者遷移到MySQL數據庫中
雖然可以用工具，但是本人還是習慣自己動手

本腳本會將分區表處理爲非分區表，如需添加分區信息，自己改腳本
本腳本只支持number，char，varchar2，date，timestamp數據類型
如需支持更多數據類型，自己修改腳本
如需將Oracle數據類型轉換爲MySQL數據類型，請看後面

set pages 10000
set feedback off
col table_ddl_in_current_user format a150
with tab_column as
 (select table_name,
         column_name,
         column_id,
         data_type,
         data_length,
         data_precision,
         data_scale,
         nullable
    from user_tab_columns),
tab as
 (select table_name from user_tables)
select case
         when column_id = 0 then
          'create table ' || lower(table_name)
       end || case
         when column_id = 1 and max_colid = 1 then
          '(' || trim(column_name)
         when column_id = 1 and max_colid <> 1 then
          '(' || trim(column_name) || ','
         when column_id > 1 and column_id < max_colid then
          column_name || ','
         when column_id = max_colid then
          column_name
       end || case
         when column_id = 999 then
          ');'
       end as table_ddl_in_current_user
  from (select table_name,
               column_id,
               max(column_id) over(partition by table_name) max_colid,
               case
                 when data_type in ('DATE', 'TIMESTAMP(6)') then
                  ' ' || lower(column_name) || ' ' || lower(data_type)
                 when data_type in ('CHAR', 'VARCHAR2') then
                  ' ' || lower(column_name) || ' ' || lower(data_type) || '(' ||
                  data_length || ')'
                 when data_type = 'NUMBER' and data_precision is not null and
                      data_scale = 0 then
                  ' ' || lower(column_name) || ' ' || lower(data_type) || '(' ||
                  data_precision || ')'
                 when data_type = 'NUMBER' and data_precision is not null and
                      data_scale > 0 then
                  ' ' || lower(column_name) || ' ' || lower(data_type) || '(' ||
                  data_precision || ',' || data_scale || ')'
                 when data_type = 'NUMBER' and data_precision is null and
                      data_scale is null then
                  ' ' || lower(column_name) || ' ' || lower(data_type)
               end || case
                 when nullable = 'N' then
                  ' not null'
               end as column_name
          from tab_column
         where table_name in (select table_name from tab)
        union all
        select table_name,
               -1         as column_id,
               null       as max_colid,
               null       as column_name
          from tab
        union all
        select table_name,
               0          as column_id,
               null       as max_colid,
               null       as column_name
          from tab
        union all
        select table_name,
               999        as column_id,
               null       as max_colid,
               null       as column_name
          from tab
         order by table_name, column_id);

抓出當前賬戶下主鍵，外鍵，索引，視圖，check約束，觸發器，函數，存儲過程等我就不貼了
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將Oracle建表語句轉爲MySQL建表語句

with tab_column
 as
 (select table_name,
         column_name,
         column_id,
         data_type,
         data_length,
         data_precision,
         data_scale,
         nullable
    from user_tab_columns ),
tab as
 (select table_name from user_tables)
select case
         when column_id = 0 then
          'create table ' || lower(table_name)
       end || case
         when column_id = 1 and max_colid = 1 then
          '(' || trim(column_name)
         when column_id = 1 and max_colid <> 1 then
          '(' || trim(column_name) || ','
         when column_id > 1 and column_id < max_colid then
          column_name || ','
         when column_id = max_colid then
          column_name
       end || case
         when column_id = 999 then
          ');'
       end as table_ddl_in_current_user
  from (select table_name,
               column_id,
               max(column_id) over(partition by table_name) max_colid,
               case
                 when data_type in ('DATE', 'TIMESTAMP(6)') then
                  ' ' || lower(column_name) || ' ' || 'datetime'
                 when data_type in ('VARCHAR2') then
                  ' ' || lower(column_name) || ' ' || 'varchar' || '(' ||
                  data_length || ')'
                  when data_type in ('CHAR') then
                  ' ' || lower(column_name) || ' ' || 'varchar' || '(' ||
                  data_length || ')' 
                 when data_type = 'NUMBER' and data_precision is not null and
                      data_scale = 0 then
                  ' ' || lower(column_name) || ' ' || 'int' || '(' ||
                  data_precision || ')'
                 when data_type = 'NUMBER' and data_precision is not null and
                      data_scale > 0 then
                  ' ' || lower(column_name) || ' ' || 'decimal' || '(' ||
                  data_precision || ',' || data_scale || ')'
                 when data_type = 'NUMBER' and data_precision is null and
                      data_scale is null then
                  ' ' || lower(column_name) || ' ' || 'int'
               end || case
                 when nullable = 'N' then
                  ' not null'
               end as column_name
          from tab_column
         where table_name in (select table_name from tab)
        union all
        select table_name,
               -1         as column_id,
               null       as max_colid,
               null       as column_name
          from tab
        union all
        select table_name,
               0          as column_id,
               null       as max_colid,
               null       as column_name
          from tab
        union all
        select table_name,
               999        as column_id,
               null       as max_colid,
               null       as column_name
          from tab
         order by table_name, column_id);