graphql-engine/server/src-rsr/mssql/mssql_update_trigger.sql.shakespeare

CREATE OR ALTER TRIGGER #{qualifiedTriggerName}
ON #{qualifiedTableName}
AFTER UPDATE
#{replicationClause}
AS
BEGIN
DECLARE @json_pk_not_updated NVARCHAR(MAX)
DECLARE @json_pk_updated NVARCHAR(MAX)

-- When primary key is not updated during a UPDATE transaction then construct both
-- 'data.old' and 'data.new'.
SET @json_pk_not_updated =
      (SELECT
          #{oldDeliveryColsSQLExp}, #{newDeliveryColsSQLExp},
          '#{operation}' as [payload.op],
          '#{schemaName}' as [schema_name],
          '#{tableName}' as [table_name],
          '#{triggerNameText}' as [trigger_name]
        FROM DELETED
        JOIN INSERTED
        ON #{primaryKeyJoinExp}
        #{listenColumnExp}
        FOR JSON PATH
      )

insert into hdb_catalog.event_log (schema_name,table_name,trigger_name,payload)
select * from OPENJSON (@json_pk_not_updated)
WITH(
  schema_name NVARCHAR(MAX) '$.schema_name',
  table_name NVARCHAR(MAX) '$.table_name',
  trigger_name NVARCHAR(MAX) '$.trigger_name',
  [payload] NVARCHAR(MAX) AS JSON
)

-- When primary key is updated during a UPDATE transaction then construct only 'data.new'
-- since according to the UPDATE Event trigger spec for MSSQL, the 'data.old' would be NULL
IF (#{isPrimaryKeyInListenColumnsExp})
  BEGIN
    SET @json_pk_updated =
          -- The following SQL statement checks, if there are any rows in INSERTED
          -- table whose primary key does not match to any rows present in DELETED
          -- table. When such an situation occurs during a UPDATE transaction, then
          -- this means that the primary key of the row was updated.
          (SELECT
            #{oldDeliveryColsSQLExpWhenPrimaryKeyUpdated}, #{newDeliveryColsSQLExpWhenPrimaryKeyUpdated},
            '#{operation}' as [payload.op],
            '#{schemaName}' as [schema_name],
            '#{tableName}' as [table_name],
            '#{triggerNameText}' as [trigger_name]
          FROM INSERTED
          WHERE NOT EXISTS (SELECT * FROM DELETED WHERE #{primaryKeyJoinExp})
          FOR JSON PATH, INCLUDE_NULL_VALUES
          )

    insert into hdb_catalog.event_log (schema_name,table_name,trigger_name,payload)
    select * from OPENJSON (@json_pk_updated)
    WITH(
      schema_name NVARCHAR(MAX) '$.schema_name',
      table_name NVARCHAR(MAX) '$.table_name',
      trigger_name NVARCHAR(MAX) '$.trigger_name',
      [payload] NVARCHAR(MAX) AS JSON
    )
  END

END;