Data Type Conversions in DQC
Reported for version 10
There are data type conversions present in DQC
Data type conversions occurrences when working with databases are the natural behaviour of DQC. When reading data from a database (e.g. using JDBC Reader step), the data type is read from the database and transformed into DQC data type. DQC internally works with its own data types. When writing the data back to the database (in such case, JDBS Writer step is commonly used), data type alternation takes place. The rules for data types conversions are defined in SQL Transformation Rules. There is a possibility to change from what exact database types there will be a conversion to DQC types.
To redefine the database types from which DQC will transform data into its own data types, go to Window > Preferences > Ataccama DQC > Database > SQL Transformation Rules and there modify SQL transformation rules of the specific database product you use.
It is also possible to either to modify the data types by performing SQL commands in your database, predefine them when using any reader step (e.g. JDBC Reader step) or to change data type manually using Create/Alter table... feature of JDBC Writer step. As a demonstration of such case, look at the following example. There are two columns written into a table, the first one of integer data type and the second one of numeric data type:
CREATE TABLE [table_name]([first_column] [int] NULL, [second_column] [numeric](10, 0) NULL)
When clicking Create/Alter table..., you get to propose to alter data type of the second column, e.g. to bigint data type:
ALTER TABLE schema_name.table_name ALTER COLUMN second_column bigint;