Use the Columns option on the INFO menu to display the following information for each column of the specified table: the name of the column, the data type of the column, and whether null values are allowed in the column.
Figure 88 shows the kind of information that you see when you select the Columns option for the cust_calls table.
Column name Type Nulls customer_num INTEGER no call_dtime DATETIME YEAR TO MINUTE yes user_id CHAR(32) yes call_code CHAR(1) yes call_descr CHAR(240) yes res_dtime DATETIME YEAR TO MINUTE yes res_descr CHAR(240) yes
The columns in Figure 88 show that the cust_calls table consists of all built-in (standard) data types. The data types available through the CREATE TABLE menu hierarchy are built-in types.
The built-in types that the Columns option can display are BOOLEAN, BYTE, CHAR, CHARACTER VARYING, DATE, DATETIME, DECIMAL, FLOAT, INT8, INTEGER, INTERVAL, MONEY, NCHAR, NVARCHAR, SERIAL, SERIAL8, SMALLFLOAT, SMALLINT, TEXT, VARCHAR, and user-defined types.
For descriptions of these data types, see the IBM Informix: Guide to SQL Reference.
Figure 89 shows the display of column information for a table that has BOOLEAN, INT8, and SERIAL8 columns as well as other built-in data types.
Column name Type Nulls id_num integer yes yes_or_no boolean yes int8col int8 yes serial8col serial8 yes text_descr char(20) yes
Large objects are built-in data types that store a large amount of data in a single column. Within a table, large-object data type columns actually contain pointers to the physical storage spaces where the database server places the large data objects.
DB–Access can display any of the following large-object data types:
The Columns option displays the specific data type for any column that contains pointers to large objects. Figure 90 shows the display of column information for a table that has a BYTE column.
Column name Type Nulls id integer yes binary_col byte yes
This section shows how DB–Access displays user-defined and complex data types for Dynamic Server.
An opaque data type characterizes data that cannot be represented by any of the built-in types that belong to the database server. DB–Access can identify and display opaque data types.
For example, suppose you assign an opaque data type called circle_t to a column named circle_col. The Columns option displays the opaque data type name in the Type column, as Figure 91 shows.
Column name Type Nulls id integer yes circle_col circle_t yes
A collection type contains zero or more elements and is more specifically defined with one of the following data type names.
DB–Access displays the specific kind of collection type in the Type column. For example, Figure 92 shows the display of a SET data type column named siblings.
Column name Type Nulls id integer yes siblings set yes
The Columns option for a table that includes a column with a row type displays the string Row in the Type column. DB–Access displays this string whether the column has a named or unnamed row type. Assume you define row type rectangle_t and assign it to column rect. Figure 93 shows that the Columns display for rect returns row rather than the specific row-type name rectangle_t as the data type.
Column name Type Nulls id integer yes rect row yes