SnowConvert AI - Teradata - SQL to JavaScript (Procedures)¶

GET DIAGNOSTICS EXCEPTION¶

Translation reference to convert Teradata GET DIAGNOSTICS EXCEPTION statement to Snowflake Scripting

Description ¶

GET DIAGNOSTICS retrieves information about successful, exception, or completion conditions from the Diagnostics Area.

For more information, see the Teradata GET DIAGNOSTICS documentation.

 GET DIAGNOSTICS
{
  [ EXCEPTION < condition_number >
    [ < parameter_name | variable_name > = < information_item > ]...
  ] 
  |
  [ < parameter_name | variable_name > = < information_item > ]...
}

Note

Some parts of the output code are omitted for clarity reasons.

Sample Source Patterns ¶

Teradata ¶

Query¶

 -- Additional Params: -t JavaScript
CREATE PROCEDURE getDiagnosticsSample ()
BEGIN
    DECLARE V_MESSAGE, V_CODE VARCHAR(200);
    DECLARE V_Result INTEGER;
    SELECT c1 INTO V_Result FROM tab1;
    GET DIAGNOSTICS EXCEPTION 1 V_MESSAGE = MESSAGE_TEXT;
END;

Snowflake ¶

Javascript¶

 CREATE OR REPLACE PROCEDURE getDiagnosticsSample ()
RETURNS STRING
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    // SnowConvert AI Helpers Code section is omitted.

    var V_MESSAGE;
    var V_CODE;
    var V_RESULT;
    EXEC(`SELECT c1 FROM tab1`,[]);
    [V_RESULT] = INTO();
    V_MESSAGE = MESSAGE_TEXT;
$$;

Known Issues¶

Unsupported condition attributes statements
1. CLASS_ORIGIN
2. CONDITION_IDENTIFIER
3. CONDITION_NUMBER
4. MESSAGE_LENGTH
5. RETURNED_SQLSTATE
6. SUBCLASS_ORIGIN

If¶

The transformation for the IF statement is:

Teradata

 IF value = 2 THEN

Snowflake

 if(value == 2){
}

Case¶

The transformation for the Case statement is:

Teradata

 case value
when 0 then
  select * from table1
else
  update table1 set name = "SpecificValue" where id = value;
end case

Snowflake

 switch(value) {
    case 0:EXEC(`SELECT * FROM PUBLIC.table1`,[]);
        break;
    default:EXEC(`UPDATE PUBLIC.table1 set name = "SpecificValue" where id = value`,[]);
        break;
}

Cursor Declare, OPEN, FETCH and CLOSE¶

The transformation for cursor statements is:

Teradata

Cursor¶

 -- Additional Params: -t JavaScript
CREATE PROCEDURE procedure1()               
DYNAMIC RESULT SETS 2
BEGIN

    -------- Local variables --------
    DECLARE sql_cmd VARCHAR(20000) DEFAULT ' '; 
    DECLARE num_cols INTEGER;
    
    ------- Declare cursor with return only-------
    DECLARE resultset CURSOR WITH RETURN ONLY FOR firststatement;

    ------- Declare cursor -------
    DECLARE cur2 CURSOR FOR SELECT COUNT(columnname) FROM table1;
    
    -------- Set --------
    SET sql_cmd='sel * from table1';
    
    -------- Prepare cursor --------
    PREPARE firststatement FROM sql_cmd; 
    
    -------- Open cursors --------
    OPEN resultset;		
    OPEN cur1;

    -------- Fetch -------------
    FETCH cur1 INTO val1, val2;
    
    -------- Close cursor --------
    CLOSE cur1;
END;

Snowflake

JavaScript Cursor¶

 CREATE OR REPLACE PROCEDURE procedure1 ()
RETURNS STRING
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    // SnowConvert AI Helpers Code section is omitted.

    //------ Local variables --------
    var SQL_CMD = ` `;
    var NUM_COLS;
    var RESULTSET = new CURSOR(() => FIRSTSTATEMENT,[],true);
    //----- Declare cursor -------
    var CUR2 = new CURSOR(`SELECT COUNT(columnname) FROM table1`,[],false);
    //------ Set --------
    SQL_CMD = `SELECT * from table1`;
    //------ Prepare cursor --------
    var FIRSTSTATEMENT = SQL_CMD;
    //------ Open cursors --------
    RESULTSET.OPEN();
    CUR1.OPEN();
    //------ Fetch -------------
    CUR1.FETCH() && ([val1,val2] = CUR1.INTO());
    //------ Close cursor --------
    CUR1.CLOSE();
    return PROCRESULTS();
$$;

While¶

The transformation for while statement is:

Teradata

While¶

 while (counter < 10) do
    set counter = counter + 1;

Snowflake¶

While¶

 while ( counter < 10) {
    counter = counter + 1;
}

Security¶

The transformation for security statements is:


Teradata	Snowflake
SQL SECURITY CREATOR	EXECUTE AS OWNER
SQL SECURITY INVOKER	EXECUTE AS CALLER
SQL SECURITY DEFINER	EXECUTE AS OWNER

FOR-CURSOR-FOR loop¶

The transformation for FOR-CURSOR-FOR loop is:

Teradata

For-Cursor-For-Loop¶

-- Additional Params: -t JavaScript
REPLACE PROCEDURE Database1.Proc1()
BEGIN
    DECLARE lNumber INTEGER DEFAULT 1;
    FOR class1 AS class2 CURSOR FOR 
      SELECT COL0,
      TRIM(COL1) AS COL1ALIAS,
      TRIM(COL2),
      COL3
      FROM someDb.prefixCol
    DO
      INSERT INTO TempDB.Table1 (:lgNumber, :lNumber, (',' || :class1.ClassCD || '_Ind CHAR(1) NOT NULL'));
      SET lNumber = lNumber + 1;
    END FOR;
END;

Snowflake

JavaScript For-Cursor-For-Loop¶

 CREATE OR REPLACE PROCEDURE Database1.Proc1 ()
RETURNS STRING
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    // SnowConvert AI Helpers Code section is omitted.

    var LNUMBER = 1;
    /*** SSC-EWI-0023 - PERFORMANCE REVIEW - THIS LOOP CONTAINS AN INSERT, DELETE OR UPDATE STATEMENT ***/
    for(var CLASS2 = new CURSOR(`SELECT
   COL0,
   TRIM(COL1) AS COL1ALIAS,
   TRIM(COL2),
   COL3
FROM
   someDb.prefixCol`,[],false).OPEN();CLASS2.NEXT();) {
        let CLASS1 = CLASS2.CURRENT;
        EXEC(`INSERT INTO TempDB.Table1
VALUES (:lgNumber, :1, (',' || :
!!!RESOLVE EWI!!! /*** SSC-EWI-0026 - THE  VARIABLE class1.ClassCD MAY REQUIRE A CAST TO DATE, TIME OR TIMESTAMP ***/!!!
:2 || '_Ind CHAR(1) NOT NULL'))`,[LNUMBER,CLASS1.CLASSCD]);
        LNUMBER = LNUMBER + 1;
    }
    CLASS2.CLOSE();
$$;

Note: The FOR loop present in the Teradata procedure is transformed to a FOR block in javascript that emulates its functionality.

Procedure parameters and variables referenced inside statements¶

The transformation for the procedure parameters and variables that are referenced inside the statements of the procedure is:

Teradata

Parameters and variables¶

 -- Additional Params: -t JavaScript
REPLACE PROCEDURE PROC1 (param1 INTEGER, param2 VARCHAR(30))
BEGIN
    DECLARE var1          VARCHAR(1024); 
    DECLARE var2          SMALLINT;
    DECLARE weekstart date;                                 
    set weekstart= '2019-03-03';
    set var1 = 'something';
    set var2 = 123;

    SELECT * FROM TABLE1 WHERE SOMETHING = :param1;
    SELECT * FROM TABLE1 WHERE var1 = var1 AND date1 = weekstart AND param2 = :param2;
    INSERT INTO TABLE2 (col1, col2, col3, col4, col5) VALUES (:param1, :param2, var1, var2, weekstart);
END;

Snowflake

JavaScript prameters and variables¶

 CREATE OR REPLACE PROCEDURE PROC1 (PARAM1 FLOAT, PARAM2 STRING)
RETURNS STRING
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    // SnowConvert AI Helpers Code section is omitted.

    var VAR1;
    var VAR2;
    var WEEKSTART;
    WEEKSTART = `2019-03-03`;
    VAR1 = `something`;
    VAR2 = 123;
    // ** SSC-EWI-0022 - ONE OR MORE IDENTIFIERS IN THIS STATEMENT WERE CONSIDERED PARAMETERS BY DEFAULT. REFERENCED TABLE NOT FOUND. **
    EXEC(`SELECT * FROM TABLE1 WHERE SOMETHING = :1`,[PARAM1]);
    // ** SSC-EWI-0022 - ONE OR MORE IDENTIFIERS IN THIS STATEMENT WERE CONSIDERED PARAMETERS BY DEFAULT. REFERENCED TABLE NOT FOUND. **
    EXEC(`SELECT * FROM TABLE1 WHERE :1 = :1 AND date1 = :2 AND param2 = :3`,[VAR1,WEEKSTART,PARAM2]);
    // ** SSC-EWI-0022 - ONE OR MORE IDENTIFIERS IN THIS STATEMENT WERE CONSIDERED PARAMETERS BY DEFAULT. REFERENCED TABLE NOT FOUND. **
    EXEC(`INSERT INTO TABLE2 (col1, col2, col3, col4, col5) VALUES (:1, :2, :3, :4, :5)`,[PARAM1,PARAM2,VAR1,VAR2,WEEKSTART]);
$$;

Note: Whenever a procedure parameter or a variable declared inside the procedure is referenced inside a Teradata statement that has to be converted, this reference is escaped from the resulting text to preserve the original reference’s functionality.

Leave¶

In Javascript, it’s possible to use break with an additional parameter, thus emulating the behavior of a Teradata LEAVE jump.

Labels can also be emulated by using Javascript Labeled Statements.

The transformation for LEAVE statement is:

Teradata

Leave¶

-- Additional Params: -t JavaScript
REPLACE PROCEDURE  PROC1 ()
BEGIN
  DECLARE v_propval            VARCHAR(1024);
 
 DECLARE Cur1 cursor for 
   Select 
      propID
   from viewName.viewCol
   where propval is not null;

LABEL_WHILE:
  WHILE (SQLCODE = 0)
  DO
      IF (SQLSTATE = '02000' ) 
       THEN LEAVE LABEL_WHILE;
      END IF;
      LABEL_INNER_WHILE:
      WHILE (SQLCODE = 0)
      DO
        IF (SQLSTATE = '02000' ) 
          THEN LEAVE LABEL_INNER_WHILE;
        END IF;
      END WHILE LABEL_INNER_WHILE;
      SELECT * FROM TABLE1;
  END WHILE L1;
END;

Snowflake

JavaScript Leave¶

 CREATE OR REPLACE PROCEDURE PROC1 ()
RETURNS STRING
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
 // SnowConvert AI Helpers Code section is omitted.

 var V_PROPVAL;
 var CUR1 = new CURSOR(`SELECT propID from viewName.viewCol
  where
  propval is not null`,[],false);
  LABEL_WHILE: {
  while ( SQLCODE == 0 ) {
   if (SQLSTATE == `02000`) {
    break LABEL_WHILE;
   }
   LABEL_INNER_WHILE: {
    while ( SQLCODE == 0 ) {
     if (SQLSTATE == `02000`) {
      break LABEL_INNER_WHILE;
     }
    }
   }
   EXEC(`SELECT * FROM TABLE1`,[]);
  }
 }
$$;

Getting Results from Procedures¶

Description of the translation¶

In Teradata, there are two ways to return data from a procedure. The first is through output parameters and the second through Dynamic Result Sets and Cursors. Both are shown in the following example. Each important point is explained below.

Example of returning data from a Stored Procedure¶

Teradata

Out parameter¶

-- Additional Params: -t JavaScript
REPLACE PROCEDURE Procedure1(OUT P1 INTEGER)               
    DYNAMIC RESULT SETS 2
    BEGIN
        DECLARE SQL_CMD,SQL_CMD_1  VARCHAR(20000) DEFAULT ' ';
        DECLARE RESULTSET CURSOR WITH RETURN ONLY FOR FIRSTSTATEMENT;
        SET SQL_CMD = 'SEL * FROM EMPLOYEE';
        PREPARE FIRSTSTATEMENT FROM SQL_CMD; 
        OPEN RESULTSET;
        SET P1 = (SEL CAST(AVG(AGE) AS INTEGER) FROM EMPLOYEE);
    END;

Snowflake

JavaScript out parameter¶

 CREATE OR REPLACE PROCEDURE Procedure1 (P1 FLOAT)
RETURNS STRING
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    // SnowConvert AI Helpers Code section is omitted.

    var SQL_CMD = ` `;
    var SQL_CMD_1 = ` `;
    var RESULTSET = new CURSOR(() => FIRSTSTATEMENT,[],true);
    SQL_CMD = `SELECT * FROM EMPLOYEE`;
    var FIRSTSTATEMENT = SQL_CMD;
    RESULTSET.OPEN();
    EXEC(`(
   SELECT
      CAST(AVG(AGE) AS INTEGER)
   FROM
      EMPLOYEE
)`,[]);
    var subQueryVariable0;
    [subQueryVariable0] = INTO();
    P1 = subQueryVariable0;
    return PROCRESULTS(P1);
$$;

In this converted SQL, there are several conversions that take place:

The DYNAMIC RESULT SETS 2 definition is converted to a DYNAMIC_RESULTS variable.

     var DYNAMIC_RESULTS = 2;
    

When a cursor with an WITH RETURNattribute is opened (and therefore a query is executed), its query ID is stored in the_OUTQUERIEScollection to be later returned. The query id is obtained by thegetQueryId()function provided in the JavaScript API for Snowflake stored procedures.
Only the first k-query-IDs are stored in the collection, where k is the value of theDYNAMIC_RESULTSvariable. This is done to emulate Teradata’s behavior, which only returns the first k-opened-cursors, even if more are opened in the stored procedure.
The combination of DECLARE CURSOR WITH RETURN with PREPARE is translated to:

     var RESULTSET = new CURSOR(() => FIRSTSTATEMENT,[],true);
    

The output parameters are supported through the return statement of the procedure. An array is created containing the value of each output parameter and the_OUTQUERIEScollection. ThePROCRESULTSfunction deals with the creation and filling of this array. See PROCRESULTS() helper for more information.

     return PROCRESULTS(P1);
    

Example of getting data from a Stored Procedure¶

If the output parameters and the query IDs are returned from a procedure, a second one could call the first one to get these values, as shown below:

Teradata

Call procedure¶

 -- Additional Params: -t JavaScript
CREATE PROCEDURE Procedure2()
BEGIN
    DECLARE x INTEGER;
    CALL Procedure1(x);
END;

Snowflake

JavaScript Call procedure¶

 CREATE OR REPLACE PROCEDURE Procedure2 ()
RETURNS STRING
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    // SnowConvert AI Helpers Code section is omitted.

    var X;
    EXEC(`CALL Procedure1(:1)`,[X]);
$$;

The value of theP1argument fromProcedure1is returned and stored in theXvariable.
The_OUTQUERIESreturned fromProcedure1are stored in theresultsetvariable.

Note

This behavior also applies to the INOUT parameters.

Known Issues¶

No issues were found.

Related EWIs¶

SSC-EWI-0022: One or more identifiers in this statement were considered parameters by default.
SSC-EWI-0023: Performance Review - A loop contains an insert, delete, or update statement.
SSC-EWI-0026: The variable may require a cast to date, time, or timestamp.
SSC-FDM-TD0001: This message is shown when SnowConvert AI finds a data type BLOB.