In This Chapter

This chapter provides an overview of the data types that the DataBlade API supports. It also describes DataBlade API support for the following types of data:

• Text and strings
• Varying-length structures
• Byte data
• Miscellaneous SQL data types: POINTER, BOOLEAN, and simple large objects
• The MI_DATUM structure
• The NULL constant

For references to discussions of different SQL data types in this manual, see Table 5.

Table 4 lists the correspondences between SQL and DataBlade API data types. To declare a variable for an SQL data type, use the appropriate DataBlade API predefined data type or structure for the variable. The mi.h header file includes the header files for the definitions of all DataBlade API data types. Include mi.h in all DataBlade API modules that use DataBlade API data types.

The DataBlade API represents the SQL data type of a column value with the following data type structures:

• A short name, called the type identifier, which identifies only the data type
• A long name, called the type descriptor, which provides the data type and information about this type