I. Introduction
In a recent test version of the project made when the export dmp when accidentally put some dirty data development library guide came out, after the test there imported into a bunch of non-standard data, in order not to affect the test results, then summed up a database data tables quickly emptied of all data.
Second, the method
(1) The first method: achieved step by step
[A] The first step: a ban on all foreign key constraints.
Open plsql, create a new query window, enter:
SELECT 'ALTER TABLE ' || table_name || ' disable CONSTRAINT ' ||
constraint_name || ';'
FROM user_constraints
where CONSTRAINT_TYPE = 'R';Open the window to be able to execute the sql
[B] Step two: Delete all the contents of the table with a delete or truncate
SELECT 'DELETE FROM ' || table_name || ';'
FROM USER_TABLES
ORDER BY TABLE_NAME;
[C] The third step: enable all foreign key constraints
SELECT 'ALTER TABLE ' || table_name || ' enable CONSTRAINT ' ||
constraint_name || ';'
FROM user_constraints
where CONSTRAINT_TYPE = 'R';
Turn after completing the implementation of these three steps, we found data in the database all the data tables are empty.
(2) The second method: execute the generated script sql, then the uniform implementation
[A] plsql open query window, execute the following script plsql
begin
dbms_output.put_line('--禁用外键SQL【开始】');
for var1 in (SELECT 'ALTER TABLE ' || table_name || ' disable CONSTRAINT ' ||
constraint_name || ';' as sqltext
FROM user_constraints
where CONSTRAINT_TYPE = 'R') loop
dbms_output.put_line(var1.sqltext);
end loop;
dbms_output.put_line('--禁用外键SQL【结束】');
dbms_output.new_line;
dbms_output.put_line('--删除表记录SQL【开始】');
for var1 in (SELECT 'DELETE FROM ' || table_name || ';' as sqltext
FROM USER_TABLES
ORDER BY TABLE_NAME) loop
dbms_output.put_line(var1.sqltext);
end loop;
dbms_output.put_line('--删除表记录SQL【结束】');
dbms_output.new_line;
dbms_output.put_line('--启用外键SQL【开始】');
for var1 in (SELECT 'ALTER TABLE ' || table_name || ' enable CONSTRAINT ' ||
constraint_name || ';' as sqltext
FROM user_constraints
where CONSTRAINT_TYPE = 'R') loop
dbms_output.put_line(var1.sqltext);
end loop;
dbms_output.put_line('--启用外键SQL【结束】');
dbms_output.new_line;
end;
[B] and then copy all of the output sql in this tab
[C] the uniform implementation of sql:
Recommended to use the second method is more simple and convenient, but if so, all related to the deletion of data should exercise caution in a production environment, to prevent users from data loss, if you can consider when there is a need to clear data using this method .