CASE
Translation reference for CASE statements
Description
The
CASE
statement chooses from a sequence of conditions and runs a corresponding statement. For more information regarding Oracle CASE, check here.
Some parts in the output code are omitted for clarity reasons.
Simple case
[ <<label>> ] CASE case_operand
WHEN boolean_expression THEN statement ;
[ WHEN boolean_expression THEN statement ; ]...
[ ELSE statement [ statement ]... ;
END CASE [ label ] ;
CASE ( <expression_to_match> )
WHEN <expression> THEN
<statement>;
[ <statement>; ... ]
[ WHEN ... ]
[ ELSE
<statement>;
[ <statement>; ... ]
]
END [ CASE ] ;
Searched case
[ <<label>> ] CASE
WHEN boolean_expression THEN statement ;
[ WHEN boolean_expression THEN statement ; ]...
[ ELSE statement [ statement ]... ;
END CASE [ label ];
CASE
WHEN <boolean_expression> THEN
<statement>;
[ <statement>; ... ]
[ WHEN ... ]
[ ELSE
<statement>;
[ <statement>; ... ]
]
END [ CASE ] ;
Sample Source Patterns
Sample auxiliar table
IN -> Oracle_01.sql
CREATE TABLE case_table(col varchar(30));
OUT -> Oracle_01.sql
CREATE OR REPLACE TABLE case_table (col varchar(30))
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
;
Simple Case
Oracle
IN -> Oracle_02.sql
CREATE OR REPLACE PROCEDURE caseExample1 ( grade NUMBER )
IS
RESULT VARCHAR(20);
BEGIN
<<CASE1>>
CASE grade
WHEN 10 THEN RESULT:='Excellent';
WHEN 9 THEN RESULT:='Very Good';
WHEN 8 THEN RESULT:='Good';
WHEN 7 THEN RESULT:='Fair';
WHEN 6 THEN RESULT:='Poor';
ELSE RESULT:='No such grade';
END CASE CASE1;
INSERT INTO CASE_TABLE(COL) VALUES (RESULT);
END;
CALL caseExample1(6);
CALL caseExample1(4);
CALL caseExample1(10);
SELECT * FROM CASE_TABLE;
|COL |
|-------------|
|Poor |
|No such grade|
|Excellent |
Snowflake Scripting
OUT -> Oracle_02.sql
CREATE OR REPLACE PROCEDURE caseExample1 (grade NUMBER(38, 18))
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$
DECLARE
RESULT VARCHAR(20);
BEGIN
!!!RESOLVE EWI!!! /*** SSC-EWI-0094 - LABEL DECLARATION FOR A STATEMENT IS NOT SUPPORTED BY SNOWFLAKE SCRIPTING <<CASE1>> ***/!!!
CASE :grade
WHEN 10 THEN
RESULT := 'Excellent';
WHEN 9 THEN
RESULT := 'Very Good';
WHEN 8 THEN
RESULT := 'Good';
WHEN 7 THEN
RESULT := 'Fair';
WHEN 6 THEN
RESULT := 'Poor';
ELSE
RESULT := 'No such grade';
END CASE;
INSERT INTO CASE_TABLE(COL) VALUES (:RESULT);
END;
$$;
CALL caseExample1(6);
CALL caseExample1(4);
CALL caseExample1(10);
--** SSC-FDM-0007 - MISSING DEPENDENT OBJECT "CASE_TABLE" **
SELECT * FROM
CASE_TABLE;
|COL |
|-------------|
|Poor |
|No such grade|
|Excellent |
Searched Case
Oracle
IN -> Oracle_03.sql
CREATE OR REPLACE PROCEDURE caseExample2 ( grade NUMBER )
IS
RESULT VARCHAR(20);
BEGIN
<<CASE1>>
CASE
WHEN grade = 10 THEN RESULT:='Excellent';
WHEN grade = 9 THEN RESULT:='Very Good';
WHEN grade = 8 THEN RESULT:='Good';
WHEN grade = 7 THEN RESULT:='Fair';
WHEN grade = 6 THEN RESULT:='Poor';
ELSE RESULT:='No such grade';
END CASE CASE1;
INSERT INTO CASE_TABLE(COL) VALUES (RESULT);
END;
CALL caseExample2(6);
CALL caseExample2(4);
CALL caseExample2(10);
SELECT * FROM CASE_TABLE;
|COL |
|-------------|
|Poor |
|No such grade|
|Excellent |
Snowflake Scripting
OUT -> Oracle_03.sql
CREATE OR REPLACE PROCEDURE caseExample2 (grade NUMBER(38, 18))
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$
DECLARE
RESULT VARCHAR(20);
BEGIN
!!!RESOLVE EWI!!! /*** SSC-EWI-0094 - LABEL DECLARATION FOR A STATEMENT IS NOT SUPPORTED BY SNOWFLAKE SCRIPTING <<CASE1>> ***/!!!
CASE
WHEN :grade = 10 THEN
RESULT := 'Excellent';
WHEN :grade = 9 THEN
RESULT := 'Very Good';
WHEN :grade = 8 THEN
RESULT := 'Good';
WHEN :grade = 7 THEN
RESULT := 'Fair';
WHEN :grade = 6 THEN
RESULT := 'Poor';
ELSE
RESULT := 'No such grade';
END CASE;
INSERT INTO CASE_TABLE(COL) VALUES (:RESULT);
END;
$$;
CALL caseExample2(6);
CALL caseExample2(4);
CALL caseExample2(10);
--** SSC-FDM-0007 - MISSING DEPENDENT OBJECT "CASE_TABLE" **
SELECT * FROM
CASE_TABLE;
|COL |
|-------------|
|Poor |
|No such grade|
|Excellent |
Known issues
1. Labels are not supported in Snowflake Scripting CASE syntax
The labels are commented out or removed depending on their position.
Related EWIS
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