有同事問有沒有ORACLE錶轉語法的小工具，於是寫了這個小函式，公開出來，也許有人用得上。

create or replace function fnc_table_to_mysql
( i_owner in string,
i_table_name in string,
i_number_default_type in string := 'decimal',
i_auto_incretment_column_name in string := '%ID'
)
/*
功能：ORACLE表生成MYSQL建表DDL
作者：葉正盛 2013-07-27
新浪微博:@yzsind-葉正盛
引數說明：
i_owner:schema名
i_table_name:表名
i_number_default_type:NUMBER預設轉換的型別，預設是decimal
i_auto_incretment_column_name:自增屬性欄位名稱規則，預設是%ID

已知問題：
1.不支援分割槽
2.不支援函式索引，點陣圖索引等特殊索引定義
3.不支援自定義資料型別，不支援ROWID,RAW等特殊資料型別
4.不支援外來鍵
5.不支援自定義約束
6.不支援與空間、事務相關屬性
7.DATE與TIMESTAMP轉換成datetime，需注意精度
8.超大NUMBER直接轉換為bigint，需注意精度
9.auto incretment 是根據欄位名規則加一些判斷，設定不一定準確，需檢查
*/
return clob is
Result clob;
cnt number;
data_type varchar2(128);
column_str varchar2(4000);
pk_str varchar2(4000);
table_comments varchar2(4000);
is_pk_column number := 0;
begin
select count(*)
into cnt
from all_tables
where owner = i_owner
and table_name = i_table_name;
if (cnt = 0) then
RAISE_APPLICATION_ERROR(-20000,'can''t found table,please check input!');
else
Result := 'CREATE TABLE `' || lower(i_table_name) || '`(';
--column
for c in (select a.column_name,
a.data_type,
a.data_length,
a.data_precision,
a.data_scale,
a.nullable,
a.data_default,
b.COMMENTS
from all_tab_cols a, all_col_comments b
where a.owner = i_owner
and a.table_name = i_table_name
and a.HIDDEN_COLUMN = 'NO'
and a.owner = b.OWNER
and a.TABLE_NAME = b.TABLE_NAME
and a.COLUMN_NAME = b.COLUMN_NAME
order by a.column_id) loop
if (c.data_type = 'VARCHAR2' or c.data_type = 'NVARCHAR2') then
data_type := 'varchar(' || c.data_length * 3 || ')';
elsif (c.data_type = 'CHAR' or c.data_type = 'NCHAR') then
data_type := 'char(' || c.data_length * 3 || ')';
elsif (c.data_type = 'NUMBER') then
if (c.column_name like '%ID' and c.data_scale is null) then
data_type := 'bigint';
elsif (c.data_precision<3 and c.data_scale = 0) then
data_type := 'tinyint';
elsif (c.data_precision<5 and c.data_scale = 0) then
data_type := 'smallint';
elsif (c.data_precision<10 and c.data_scale = 0) then
data_type := 'int';
elsif (c.data_precision is not null and c.data_scale = 0) then
data_type := 'bigint';
elsif (c.data_precision is not null and c.data_scale is not null) then
data_type := 'decimal(' || c.data_precision || ',' ||
c.data_scale || ')';
else
data_type := i_number_default_type;
end if;
elsif (c.data_type = 'DATE' or c.data_type like 'TIMESTAMP%') then
data_type := 'datetime';
elsif (c.data_type = 'CLOB' or c.data_type = 'NCLOB' or
c.data_type = 'LONG') then
data_type := 'text';
elsif (c.data_type = 'BLOB' or c.data_type = 'LONG RAW') then
data_type := 'blob';
elsif (c.data_type = 'BINARY_FLOAT') then
data_type := 'float';
elsif (c.data_type = 'BINARY_DOUBLE') then
data_type := 'double';
elsif (c.data_type like 'RAW%') then
data_type := 'blob(' || c.data_length || ')';
else
data_type := c.data_type;
end if;
column_str := ' `' || lower(c.column_name) || '` ' || data_type;
if (c.column_name like i_auto_incretment_column_name and
(c.data_scale is null or c.data_scale = 0)) then
select count(*)
into is_pk_column
from all_constraints a, all_cons_columns b
where a.owner = i_owner
and a.table_name = i_table_name
and a.constraint_type = 'P'
and a.OWNER = b.OWNER
and a.TABLE_NAME = b.TABLE_NAME
and a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
and b.COLUMN_NAME = c.column_name;
if is_pk_column > 0 then
column_str := column_str || ' AUTO_INCREMENT';
end if;
end if;
if c.nullable = 'NO' then
column_str := column_str || ' NOT NULL';
end if;
if (trim(c.data_default) is not null) then
column_str := column_str || ' DEFAULT ' ||
trim(replace(replace(c.data_default, chr(13), ''),
chr(10),
''));
end if;
if c.comments is not null then
column_str := column_str || ' COMMENT ''' || c.comments || '''';
end if;
Result := Result || chr(10) || column_str || ',';
end loop;
--pk
for c in (select a.constraint_name, wm_concat(a.column_name) pk_columns
from (select a.CONSTRAINT_NAME,
'`' || b.COLUMN_NAME || '`' column_name
from all_constraints a, all_cons_columns b
where a.owner = i_owner
and a.table_name = i_table_name
and a.constraint_type = 'P'
and a.OWNER = b.OWNER
and a.TABLE_NAME = b.TABLE_NAME
and a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
order by b.POSITION) a
group by a.constraint_name) loop
Result := Result || chr(10) || ' PRIMARY KEY (' ||
lower(c.pk_columns) || '),';
end loop;
--unique
for c in (select a.constraint_name, wm_concat(a.column_name) uk_columns
from (select a.CONSTRAINT_NAME,
'`' || b.COLUMN_NAME || '`' column_name
from all_constraints a, all_cons_columns b
where a.owner = i_owner
and a.table_name = i_table_name
and a.constraint_type = 'U'
and a.OWNER = b.OWNER
and a.TABLE_NAME = b.TABLE_NAME
and a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
order by b.POSITION) a
group by a.constraint_name) loop
Result := Result || chr(10) || ' UNIQUE KEY `' ||
lower(c.constraint_name) || '`(' || lower(c.uk_columns) || '),';
end loop;
-- index
for c in (select a.index_name, wm_concat(a.column_name) ind_columns
from (select a.index_name,
'`' || a.COLUMN_NAME || '`' column_name
from all_ind_columns a
where a.table_owner = i_owner
and a.TABLE_NAME = i_table_name
and not exists
(select index_name
from all_constraints b
where a.TABLE_OWNER = b.owner
and a.TABLE_NAME = b.TABLE_NAME
and a.INDEX_NAME = b.INDEX_NAME)
order by a.COLUMN_POSITION) a
group by a.index_name) loop
Result := Result || chr(10) || ' KEY `' || lower(c.index_name) || '`(' ||
lower(c.ind_columns) || '),';
end loop;
Result := substr(Result, 1, length(result) - 1) || chr(10) || ')';
--table comments
select max(a.COMMENTS)
into table_comments
from all_tab_comments a
where owner = i_owner
and table_name = i_table_name;
if (table_comments is not null) then
Result := Result || 'COMMENT=''' || table_comments || '''';
end if;
Result := Result || ';';
end if;
return(Result);
end fnc_table_to_mysql;

ORACLE表生成MYSQL建表DDL

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