Working with Data Types and Data Display Formats
Data Types
Data types control the type of information a column can contain and determine how the Data Manager carries out particular operations. By assigning the correct data type to each column in a table, you can implement and execute many operations more easily.
Data types are significant in working with a relational database because when you add or change data in a column, the new data must be of the type specified for that column when the table was created. For example, you cannot accidentally store a date in a salary field designated for the money data type.
There are four fundamental data types:
• Character (or text)
• Numeric
• Date
• Money
These data types may not all be compatible with Enterprise Access products. The character and numeric data types are broken into subsets. For example, integers can be stored as 1‑byte, 2‑byte, and 4‑byte integers. Data types are named differently in SQL and QUEL. For more information, see the appendix "Data Types" for OpenSQL and QUEL data types.
c(n)
Fixed-length string of up to n printable ASCII characters, with non-printable characters converted to blank; n represents the lesser of the maximum configured row size and 32,000.
char(n)
Fixed-length string of up to n ASCII characters, including any non-printable characters; n represents the lesser of the maximum configured row size and 32,000.
varchar(n)
Variable-length ASCII character string of up to n characters; n represents the lesser of the maximum configured row size and 32,000.
text(n)
Variable-length string of up to n ASCII characters; n represents the lesser of the maximum configured row size and 32,000.
float(n)
n-byte floating point; converted to a 4‑byte or 8‑byte floating point data type.
float4
4‑byte floating point; for numbers including decimal fractions, from 0.29x10**‑38 to 1.7x10**38 with 7 digit precision.
float8
8‑byte floating point; for numbers including decimal fractions, from 0.29x10**‑38 to 1.7x10**38 with 16 digit precision.
decimal
Exact numeric data type defined by its precision (total number of digits) and scale (number of digits to the right of the decimal point). Precision must be between 1 and 31. Scale can be zero (0) up to the maximum scale.
integer1
1‑byte integer; for whole numbers ranging from ‑128 to +127.
integer2 or smallint
2‑byte integer; for whole numbers ranging from ‑32,768 to +32,767.
integer4 or integer
4‑byte integer; for whole numbers ranging from ‑2,147,483,648 to +2,147,483,647.
money
8 byte monetary data; from ‑$999999999999.99 to +$999999999999.99.
date
12 bytes; dates ranging from 1/1/1582 to 12/31/2382 for absolute dates and ‑800 years to +800 years for time intervals.
A user‑defined data type (UDT) is perceived and treated as a character string.
Some forms utilities do not support the long varchar, byte, byte varying, and long byte data types. For more information, see each specific product for a discussion of how long varchar, byte, byte varying, and long byte is handled.
Last modified date: 01/30/2023