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Add SSMA articles for ROWID conversion messages
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‎docs/ssma/db2/messages/db22ss0028.md‎

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---
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title: "DB22SS0028: ROWID column generated (Info)"
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description: "Describes the reason why SQL Server Migration Assistant (SSMA) for DB2 adds ROWID column to the table."
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author: "nahk-ivanov"
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ms.prod: sql
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ms.technology: ssma
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ms.devlang: "sql"
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ms.topic: "article"
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ms.date: "10/15/2020"
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ms.author: "alexiva"
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---
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# DB22SS0028: `ROWID` column generated (Info)
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This article describes the reason why SQL Server Migration Assistant (SSMA) for DB2 adds `ROWID` column to the table, if there are triggers.
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## Background
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In DB2 you can create a trigger that will run `FOR EACH ROW`, rather than for the entire set of rows that is changing. In SQL Server triggers always execute for the entire set of modified rows. If row-level DB2 trigger accesses both - `OLD` and `NEW` correlation names, then SSMA needs a way to match rows from both row sets in order to identify what the value was for a given row before and after the update. To emulate such "for each row" functionality, SSMA adds special `ROWID` column to uniquely identify each modified row and uses it to establish a relationship between `inserted` and `deleted` row sets.
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## Example
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Consider the following DB2 trigger, that executes for each row updated in `TRIG_TEST` table:
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```sql
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CREATE OR REPLACE TRIGGER TSCHM.TRIG_TEST_AU
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AFTER UPDATE OF DATA ON TSCHM.TRIG_TEST
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REFERENCING OLD AS O NEW AS N
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FOR EACH ROW
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MODE DB2SQL
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BEGIN ATOMIC
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IF (N.DATA = 'ABC') THEN
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INSERT INTO TSCHM.TRIG_TEST(DATA) VALUES ('-' || O.DATA);
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END IF;
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END
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```
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When you try to convert this trigger in SSMA, the following T-SQL will be produced within the SQL Server trigger:
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1) Run a cursor over `inserted` row set, selecting `ROWID` and `DATA` columns into `@new$0` and `@new$DATA` variables:
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```sql
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DECLARE
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ForEachInsertedRowTriggerCursor CURSOR LOCAL FORWARD_ONLY READ_ONLY FOR
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SELECT ROWID, DATA
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FROM inserted
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OPEN ForEachInsertedRowTriggerCursor
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FETCH ForEachInsertedRowTriggerCursor
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INTO @new$0, @new$DATA
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```
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2) Select matching row from `deleted` row set into `@old$0` and `@old$DATA` variables, based on the inserted `ROWID` (stored in `@new$0` variable):
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```sql
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SELECT @old$0 = ROWID, @old$DATA = DATA
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FROM deleted
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WHERE ROWID = @new$0
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```
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3) Perform trigger actions using `@old$DATA`/`@new$DATA` variables:
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```sql
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IF (@new$DATA = 'ABC')
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INSERT SSMAADMIN.TRIG_TEST(DATA)
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VALUES (('-' + ISNULL(@old$DATA, '')))
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```
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## Additional information
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This behavior is controlled by the **Generate ROWID column** project setting, which can be found under **Tools** - **Project Settings** - **General** - **Conversion** - **ROWID generation**. If the setting is **Off**, but during trigger conversion SSMA identifies that it requires a `ROWID` column, then [DB22SS0239](db22ss0239.md) conversion error will be generated.
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## Related conversion messages
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* [DB22SS0239: ROWID column not accessible](db22ss0239.md)
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* DB22SS0267: ROWID column
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* DB22SS0404: ROWID column can not be converted

‎docs/ssma/db2/messages/db22ss0239.md‎

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---
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title: "DB22SS0239: ROWID column not accessible (Error)"
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description: "Describes the reason why SQL Server Migration Assistant (SSMA) for DB2 requires a ROWID column to be defined."
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author: "nahk-ivanov"
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ms.prod: sql
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ms.technology: ssma
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ms.devlang: "sql"
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ms.topic: "article"
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ms.date: "10/15/2020"
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ms.author: "alexiva"
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---
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# DB22SS0239: `ROWID` column not accessible (Error)
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This article describes the reason why SQL Server Migration Assistant (SSMA) for DB2 requires a `ROWID` column to be defined for the table with triggers.
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## Background
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In DB2 you can create a trigger that will run `FOR EACH ROW`, rather than for the entire set of rows that is changing. In SQL Server triggers always execute for the entire set of modified rows. If row-level DB2 trigger accesses both - `OLD` and `NEW` correlation names, then SSMA needs a way to match rows from both row sets in order to identify what the value was for a given row before and after the update. To emulate such "for each row" functionality, SSMA adds special `ROWID` column to uniquely identify each modified row and uses it to establish a relationship between `inserted` and `deleted` row sets.
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This behavior is controlled by the **Generate ROWID column** project setting, which can be found under **Tools** - **Project Settings** - **General** - **Conversion** - **ROWID generation**. If the setting is **Off**, then `ROWID` column will not be added to the table and SSMA will not be able to convert such triggers.
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## Example
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Consider the following DB2 trigger, that executes for each row updated in `TRIG_TEST` table:
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```sql
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CREATE OR REPLACE TRIGGER TSCHM.TRIG_TEST_AU
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AFTER UPDATE OF DATA ON TSCHM.TRIG_TEST
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REFERENCING OLD AS O NEW AS N
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FOR EACH ROW
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MODE DB2SQL
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BEGIN ATOMIC
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IF (N.DATA = 'ABC') THEN
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INSERT INTO TSCHM.TRIG_TEST(DATA) VALUES ('-' || O.DATA);
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END IF;
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END
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```
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When you try to convert this trigger in SSMA, if the **Generate ROWID column** project setting is **Off**, then SSMA will generate the following error message:
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> DB22SS0239: ROWID column not accessible
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## Possible remedies
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Change the **Generate ROWID column** project setting to **On**, this will allow SSMA to produce the following T-SQL within the SQL Server trigger when converting the above example:
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1) Run a cursor over `inserted` row set, selecting `ROWID` and `DATA` columns into `@new$0` and `@new$DATA` variables:
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```sql
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DECLARE
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ForEachInsertedRowTriggerCursor CURSOR LOCAL FORWARD_ONLY READ_ONLY FOR
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SELECT ROWID, DATA
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FROM inserted
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OPEN ForEachInsertedRowTriggerCursor
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FETCH ForEachInsertedRowTriggerCursor
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INTO @new$0, @new$DATA
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```
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2) Select matching row from `deleted` row set into `@old$0` and `@old$DATA` variables, based on the inserted `ROWID` (stored in `@new$0` variable):
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```sql
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SELECT @old$0 = ROWID, @old$DATA = DATA
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FROM deleted
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WHERE ROWID = @new$0
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```
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3) Perform trigger actions using `@old$DATA`/`@new$DATA` variables:
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```sql
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IF (@new$DATA = 'ABC')
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INSERT SSMAADMIN.TRIG_TEST(DATA)
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VALUES (('-' + ISNULL(@old$DATA, '')))
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```
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## Related conversion messages
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* [DB22SS0028: ROWID column generated](db22ss0028.md)
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* DB22SS0267: ROWID column
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* DB22SS0404: ROWID column can not be converted

‎docs/ssma/db2/messages/toc.yml‎

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- name: DB22SS0028
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href: db22ss0028.md
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- name: DB22SS0239
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href: db22ss0239.md
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- name: DB22SS0573
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href: db22ss0573.md

‎docs/ssma/oracle/messages/o2ss0028.md‎

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---
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title: "O2SS0028: ROWID column generated (Info)"
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description: "Describes the reason why SQL Server Migration Assistant (SSMA) for Oracle adds ROWID column to the table."
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author: "nahk-ivanov"
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ms.prod: sql
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ms.technology: ssma
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ms.devlang: "sql"
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ms.topic: "article"
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ms.date: "10/15/2020"
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ms.author: "alexiva"
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---
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# O2SS0028: `ROWID` column generated (Info)
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This article describes the reason why SQL Server Migration Assistant (SSMA) for Oracle adds `ROWID` column to the table, if there are triggers.
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## Background
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In Oracle you can create a trigger that will run `FOR EACH ROW`, rather than for the entire set of rows that is changing. In SQL Server triggers always execute for the entire set of modified rows. If row-level Oracle trigger accesses both - `:old` and `:new` special variables, then SSMA needs a way to match rows from both row sets in order to identify what the value was for a given row before and after the update. To emulate such "for each row" functionality, SSMA adds special `ROWID` column to uniquely identify each modified row and uses it to establish a relationship between `inserted` and `deleted` row sets.
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## Example
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Consider the following Oracle trigger, that executes for each row updated in `TRIG_TEST` table:
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```sql
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CREATE OR REPLACE TRIGGER TSCHM.TRIG_TEST_AU
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AFTER UPDATE OF DATA ON TSCHM.TRIG_TEST
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FOR EACH ROW
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BEGIN
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IF (:new.DATA = 'ABC') THEN
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INSERT INTO TSCHM.TRIG_TEST(DATA) VALUES ('-' || :old.DATA);
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END IF;
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END;
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```
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When you try to convert this trigger in SSMA, the following T-SQL will be produced within the SQL Server trigger:
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1) Run a cursor over `inserted` row set, selecting `ROWID` and `DATA` columns into `@new$0` and `@new$DATA` variables:
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```sql
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DECLARE
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ForEachInsertedRowTriggerCursor CURSOR LOCAL FORWARD_ONLY READ_ONLY FOR
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SELECT ROWID, DATA
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FROM inserted
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OPEN ForEachInsertedRowTriggerCursor
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FETCH ForEachInsertedRowTriggerCursor
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INTO @new$0, @new$DATA
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```
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2) In a loop, select matching row from `deleted` row set into `@old$0` and `@old$DATA` variables, based on the inserted `ROWID` (stored in `@new$0` variable):
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```sql
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SELECT @old$0 = ROWID, @old$DATA = DATA
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FROM deleted
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WHERE ROWID = @new$0
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```
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3) Perform trigger actions using `@old$DATA`/`@new$DATA` variables:
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```sql
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IF (@new$DATA = 'ABC')
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INSERT SSMAADMIN.TRIG_TEST(DATA)
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VALUES (('-' + ISNULL(@old$DATA, '')))
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```
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## Additional information
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This behavior is controlled by the **Generate ROWID column** project setting, which can be found under **Tools** - **Project Settings** - **General** - **Conversion** - **ROWID generation**. If the setting is **Off**, but during trigger conversion SSMA identifies that it requires a `ROWID` column, then [O2SS0239](o2ss0239.md) conversion error will be generated.
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## Related conversion messages
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* [O2SS0239: ROWID column not accessible](o2ss0239.md)
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* O2SS0267: ROWID column
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* O2SS0404: ROWID column can not be converted

‎docs/ssma/oracle/messages/o2ss0239.md‎

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---
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title: "O2SS0239: ROWID column not accessible (Error)"
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description: "Describes the reason why SQL Server Migration Assistant (SSMA) for Oracle requires a ROWID column to be defined."
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author: "nahk-ivanov"
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ms.prod: sql
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ms.technology: ssma
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ms.devlang: "sql"
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ms.topic: "article"
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ms.date: "10/15/2020"
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ms.author: "alexiva"
11+
---
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13+
# O2SS0239: `ROWID` column not accessible (Error)
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15+
This article describes the reason why SQL Server Migration Assistant (SSMA) for Oracle requires a `ROWID` column to be defined for the table with triggers.
16+
17+
## Background
18+
19+
In Oracle you can create a trigger that will run `FOR EACH ROW`, rather than for the entire set of rows that is changing. In SQL Server triggers always execute for the entire set of modified rows. If row-level Oracle trigger accesses both - `:old` and `:new` special variables, then SSMA needs a way to match rows from both row sets in order to identify what the value was for a given row before and after the update. To emulate such "for each row" functionality, SSMA adds special `ROWID` column to uniquely identify each modified row and uses it to establish a relationship between `inserted` and `deleted` row sets.
20+
21+
This behavior is controlled by the **Generate ROWID column** project setting, which can be found under **Tools** - **Project Settings** - **General** - **Conversion** - **ROWID generation**. If the setting is **Off**, then `ROWID` column will not be added to the table and SSMA will not be able to convert such triggers.
22+
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## Example
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Consider the following Oracle trigger, that executes for each row updated in `TRIG_TEST` table:
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27+
```sql
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CREATE OR REPLACE TRIGGER TSCHM.TRIG_TEST_AU
29+
AFTER UPDATE OF DATA ON TSCHM.TRIG_TEST
30+
FOR EACH ROW
31+
BEGIN
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IF (:new.DATA = 'ABC') THEN
33+
INSERT INTO TSCHM.TRIG_TEST(DATA) VALUES ('-' || :old.DATA);
34+
END IF;
35+
END;
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```
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When you try to convert this trigger in SSMA, if the **Generate ROWID column** project setting is **Off**, then SSMA will generate the following error message:
39+
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> O2SS0239: ROWID column not accessible
41+
42+
## Possible remedies
43+
44+
Change the **Generate ROWID column** project setting to **On**, this will allow SSMA to produce the following T-SQL within the SQL Server trigger when converting the above example:
45+
46+
1) Run a cursor over `inserted` row set, selecting `ROWID` and `DATA` columns into `@new$0` and `@new$DATA` variables:
47+
48+
```sql
49+
DECLARE
50+
ForEachInsertedRowTriggerCursor CURSOR LOCAL FORWARD_ONLY READ_ONLY FOR
51+
SELECT ROWID, DATA
52+
FROM inserted
53+
54+
OPEN ForEachInsertedRowTriggerCursor
55+
56+
FETCH ForEachInsertedRowTriggerCursor
57+
INTO @new$0, @new$DATA
58+
```
59+
60+
2) Select matching row from `deleted` row set into `@old$0` and `@old$DATA` variables, based on the inserted `ROWID` (stored in `@new$0` variable):
61+
62+
```sql
63+
SELECT @old$0 = ROWID, @old$DATA = DATA
64+
FROM deleted
65+
WHERE ROWID = @new$0
66+
```
67+
68+
3) Perform trigger actions using `@old$DATA`/`@new$DATA` variables:
69+
70+
```sql
71+
IF (@new$DATA = 'ABC')
72+
INSERT SSMAADMIN.TRIG_TEST(DATA)
73+
VALUES (('-' + ISNULL(@old$DATA, '')))
74+
```
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## Related conversion messages
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78+
* [O2SS0028: ROWID column generated](o2ss0028.md)
79+
* O2SS0267: ROWID column
80+
* O2SS0404: ROWID column can not be converted

‎docs/ssma/oracle/messages/toc.yml‎

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href: o2ss0007.md
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- name: O2SS0021
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href: o2ss0021.md
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- name: O2SS0028
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href: o2ss0028.md
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- name: O2SS0029
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href: o2ss0029.md
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- name: O2SS0038
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href: o2ss0217.md
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- name: O2SS0221
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href: o2ss0221.md
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- name: O2SS0239
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href: o2ss0239.md
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- name: O2SS0245
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href: o2ss0245.md
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- name: O2SS0260

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