SQL Modify field Default value

First, SQL Modify field default value

1. ALTER TABLE name DROP CONSTRAINT constraint name
3. Description: Delete the original constraint for a table field
4. ALTER TABLE name ADD constraint constraint first name default value for field name
6. Description: Add a constraint for a table's field and specify a default value
8. Go

Cases:

1. ALTER TABLE t_ping DROP constraint Df_t_ping_p_c
2. ALTER TABLE t_ping add constraint Df_t_ping_p_c DEFAULT ((2)) for P_c
3. Go

Second, get the field default value

1. Select B.text as Default field name (Random)
2. From syscolumns a LEFT join syscomments B on a.cdefault=b.id
3. where a.id=object_id (' table name ') and a.name= ' field name '

Description: syscolumns, syscomments for system table

Cases:

1. Select B.text as Moren
3. From syscolumns a LEFT join syscomments B on a.cdefault=b.id
4. where a.id=object_id (' t_ping ') and a.name= ' P_c '

After getting the quotation marks, you can intercept the characters

SQL Modify field Default value