MySQL and mSQL

SQL Datatypes

In a table, each column has a type. As we mentioned earlier, a SQL datatype is similar to a datatype in traditional programming languages. While many languages define a bare-minimum set of types necessary for completeness, SQL goes out of its way to provide types such as MONEY and DATE that will be useful to every day users. You could store a MONEY type in a more basic numeric type, but having a type specifically dedicated to the nuances of money processing helps add to SQL’s ease of use—one of SQL’s primary goals.

Chapter 15, provides a full reference of SQL types supported by MySQL or mSQL. Table 6.1 is an abbreviated listing of the most common types supported in both languages.

Table 6-1. The Most Often Used Datatypes Common to Both MySQL and mSQL

Datatype	Description
INT	An integer value. MySQL allows an INT to be either signed or unsigned, while mSQL provides a distinct type, UINT, for unsigned integers.
REAL	A floating point value. This type offers a greater range and precision than the INT type, but it does not have the exactness of an INT.
CHAR(length)	A fixed-length character value. No CHAR fields can hold strings greater in length than the specified value. Fields of lesser length are padded with spaces. This type is likely the most commonly used type in any SQL implementation.
TEXT(length)	A variable length character value. In mSQL, the given length is used as a suggestion as to how long the strings being stored will be. You may store larger values, ...