Data types

Data types in a meta-schema have the same meaning for every supported database type.

If needed, the data type will be converted to the appropriate target database type when generating a database creation / update script. See the SQL adaptation guides in the Genero Business Development Language User Guide for more information on the use of data types in your database.

Table 1. Common data types
Type	Description
BIGINT	The `BIGINT` data type is used for storing very large whole numbers.
BIGSERIAL	The `BIG SERIAL` data type produces automatic integer sequences. `BIGSERIAL` is based on 64 bit integer sequences.
BOOLEAN	The `BOOLEAN` data type stores a logical value, TRUE or FALSE.
BYTE	The `BYTE` data type stores any type of binary data, such as images or sounds.
CHAR	The `CHAR` data type is a fixed-length character string data type.
DATE	The `DATE` data type stores calendar dates with a Year/Month/Day representation.
DATETIME	The `DATETIME` data type stores date and time data with time units from the year to fractions of a second.
DECIMAL	The `DECIMAL` data type is provided to handle large numeric values with exact decimal storage.
FLOAT	The `FLOAT` data type stores values as double-precision floating-point binary numbers with up to 16 significant digits.
INTEGER	The `INTEGER` data type is used for storing large whole numbers.
SERIAL	The `SERIAL` data type produces automatic integer sequences. `SERIAL` is based on 32 bit integer sequences.
SMALLFLOAT	The `SMALLFLOAT` data type stores values as single-precision floating-point binary numbers with up to 8 significant digits.
SMALLINT	The `SMALLINT` data type is used for storing small whole numbers.
TEXT	The `TEXT` data type stores large text data.
VARCHAR	The `VARCHAR` data type is a variable-length character string data type, with a maximum size. It is converted to the appropriate target database type when generating database creation / update script.

Table 2. Informix® specific data types
Type	Description
INTERVAL	The `INTERVAL` data type stores spans of time as Year/Month or Day/Hour/Minute/Second/Fraction units.
MONEY	The `MONEY` data type is provided to store currency amounts with exact decimal storage.
NCHAR / NVARCHAR	IBM® Informix® supports the standard `NCHAR` and `NVARCHAR` data types. These types are equivalent to `CHAR` and `VARCHAR` (the same character set is used), except that the collation order is locale specific with `NCHAR`/ `NVARCHAR` types.

Informix specific types should be avoided when designing databases. A warning is displayed when a column uses an Informix specific type: INT8, INTERVAL, MONEY, NCHAR, NVARCHAR, NVARCHAR2, SERIAL8. To correct this warning convert columns to a common data type:

INT8 to BIGINT
MONEY to DECIMAL
SERIAL8 to BIGSERIAL
NCHAR / NVARCHAR / NVARCHAR2 to CHAR / VARCHAR and check the Use national char types option when generating database scripts
avoid using INTERVAL

Note: The internal data type is used when generating database creation / update scripts or when working with the Business Application Modeler. However, if you edit a data type in a schema from the extracted database, the generic data type used in the creation of the schema might change the internal data type. For example, a column extracted from an Informix® database of type INT8 will be displayed in the schema as BIGINT. If the you change the type definition in the schema back to BIGINT, the database creation / update scripts will this time create a column of type BIGINT in the Informix® database.