Create table but Drop it if the table exists already

Question

I am working on a request where I have to create a table to insert some data. So, obviously I will have first have a delete table st. before the create st. but when I am run

Answer 1

You can create a stored procedure owned by SYSDBA or other admin level user with adequate DROP TABLE and CREATE TABLE privileges that does the following:

1. Check DBC.Tables to see if object exists.
2. If object exists, drop it.
3. Run the DDL to recreate the table: CREATE TABLE <TargetDB>.<TargetTable> AS <SourceDB>.<SourceTable> WITH DATA AND STATS;

You can make it more dynamic by accepting additional parameters on whether the data and/or stats should be copied to the new table.

If you are using BTEQ, you can do something similar (BTEQ command syntax may be a little off but close enough to get the point across):

SELECT 1 
FROM DBC.TABLES 
WHERE DatabaseName = '<TargetDB>'
  AND TableName = '<TargetTable>'
  AND TableKind = 'T' /* Make sure it is in fact a table, not a view, macro etc */


.IF ACIVITYCOUNT = 0 THEN GOTO CreateNewTable;

DROP TABLE <TargetDB>.<TargetTable>;

.IF ERRORCODE = 3807 THEN GOTO CreateNewTable; /* Table dropped by another process? */
.IF ERRORCODE > 0 THEN .QUIT ERRORCODE; /* Unexpected error */

.LABEL CreateNewTable;

CREATE <TargetDB>.<TargetTable> AS <SourceDB>.<SourceTable> WITH DATA AND STATISTICS;

Answer 2

It seems SAS proc sql cannot do it like T-SQL directly. Anyway, you can write a macro to check if the data set exist. If so, drop it first. Then create the table. Like the following code.

%macro checkDrop(tmpData);
%if %SYSFUNC(exist(&tmpData)) %then %do;
    proc sql;
    drop table &tmpData;
    quit;
    %end;
    %else %do;
    proc sql;
    create table &tmpData (a numberic, b numberic);
    %end;
%mend;
%checkDrop(tmp)