Modify the length value of a table field
Syntax:
Alter table alter column new type name (length)
The field length has changed from varchar (max) to varchar (3000).
Alter table Engage_Job_JianLi alter column emp_gzjl varchar (3000)
Select * from emp_certificate
-- back up the table first
Select * into emp_certificate0620 from emp_certificate
-- modify the length of the field
Alter table emp_certificate alter column Cert_code varchar (30)
