SQL Sever-t-sql determine if there are (databases, tables, stored procedures, constraints ...) and columns)

If db_id (N ' DATABASENAME ') is not null

Use databasename--jump to the specified database

Go

If OBJECT_ID (n ' a ', n ' U ') is not null

drop Table A

Go

Note: A is a table and U represents a data table type

Type code similar to U, as shown below

Object type:

AF = aggregate function (CLR)

C = CHECK Constraint

D = DEFAULT (constrained or standalone)

F = FOREIGN KEY constraint

PK = PRIMARY KEY constraint

P = SQL Stored Procedure

PC = assembly (CLR) stored procedure

FN = SQL scalar function

FS = assembly (CLR) scalar functions

FT = assembly (CLR) table-valued function

R = Rule (Legacy, standalone)

RF = Replication filtering process

SN = synonym

TR = SQL DML Trigger

IF = SQL Inline Table-valued function

TF = SQL Table-valued function

U = table (user-defined type)

UQ = UNIQUE Constraint

V = view

X = Extended Stored Procedure

IT = Internal table

I've introduced sysobjects this system table before. Custom tables, stored procedures ..... will be stored in this form. So.....

  If col_length (,  C ' )  is not null              

Note: A is a table name

    C is the column  name

Or:

Select*from   syscolumns       id=object_id ( table name ' )    and   name= column name '              

Note: A description record of this column is returned, and there is no return null;

SQL Sever-t-sql determine if there are (databases, tables, stored procedures, constraints ...) and columns)