迁移postgres时序列错误脚本修复

Posted 2021-03-01 raspberry-zx

迁移postgres数据库的时候,有时候会出现序列与数据库值不匹配的现象.参考了https://stackoverflow.com/questions/244243/how-to-reset-postgres-primary-key-sequence-when-it-falls-out-of-sync之后,

改写了一下脚本,执行后可正常使用了.

 1 do --check seq not in sync
 2 $$
 3 declare
 4  _r record;
 5  _i bigint;
 6  _m bigint;
 7 begin
 8   for _r in (
 9     Select
10       DISTINCT(constraint_column_usage.table_name) as tablename,
11       constraint_column_usage.column_name as idname,
12       replace(replace(columns.column_default,‘‘‘::regclass)‘,‘‘),‘nextval(‘‘‘,‘‘) as seqname,
13             columns.table_schema as schamename
14       from information_schema.constraint_column_usage, information_schema.columns
15       where constraint_column_usage.table_schema =‘public‘ AND 
16       columns.table_schema = ‘public‘ AND columns.table_name=constraint_column_usage.table_name
17       AND constraint_column_usage.column_name = columns.column_name
18       AND columns.column_default is not null 
19    ) loop
20     execute format(‘select last_value from %I.%s‘,_r.schamename,_r.seqname) into _i;
21     execute format(‘select max(%I) from %I.%I‘,_r.idname,_r.schamename,_r.tablename) into _m;
22     if coalesce(_m,0) > _i then
23       raise info ‘%‘,concat(‘changed: ‘,_r.tablename||‘_Id_seq‘,‘ from:‘,_i,‘ to:‘,_m);
24       execute format(‘alter sequence %I.%I restart with %s‘,_r.schamename,_r.seqname,_m);
25     end if;
26   end loop;
27 
28 end;
29 $$
30 ;

使用的时候根据实际情况修改一下 schema的值就好