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Centrallix Documentation
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6.7 Data Types
Centrallix Data Types
Centrallix has six fundamental data types that are common in SQL queries. While there are other data types in Centrallix, support for them is currently somewhat limited, or their use is specialized and not applicable to the SQL language.
| DataType | Description |
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| integer | A whole number with no fraction part, 32 bit, which can be positive or negative ranging from -2147483648 to 2147483647. |
| string | A sequence of characters (bytes). Strings in Centrallix SQL do not have inherent length limits (as in char and varchar data types), as such length limits are considered a physical data source issue. String constants are in single or double quotation marks. Quote marks occurring inside the string are escaped with a backslash. |
| double | A double-precision floating point value. Floating-point constants are represented via the use of the decimal point. |
| datetime | A combined date and time value. There is no Centrallix data type representing only a time or only a date. There is also no way of inherently representing a datetime constant; usually they are written as strings, but convert() can be used if a more explicit method of representing them is desired. |
| money | A numeric fixed-point data type having a 32-bit whole part and a fraction part that can range from 0000 to 9999. Money constants are represented in Centrallix by starting them with a dollar sign ($), although when printing such values, the dollar sign does not need to appear (in order to properly view non-dollar currencies). |
| binary | A binary 8-bit-clean character sequence. It is similar to a string, but it is counted instead of nul-terminated.
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Data Representation and Presentation
Most SQL's have the concept of a string value being limited in length or having a fixed length.
Centrallix represents such limitations either at the data source level, where they are a storage or performance optimization, or else using a mechanism known as Presentation Hints. Any attribute may have presentation hints associated with it, which can provide additional information about the inherent limits associated with an attribute (and much much more).
For example, if an integer in a data source is an 8-bit unsigned integer, Centrallix will use its 32-bit signed integer data type, but will attach "Presentation Hints" to the attribute which set a minimum value of 0 and a maximum value of 255.
For a second example, if a string is a varchar(20) in the data source, Centrallix will represent it as a string with presentation hints that set a maximum length of 20 characters.
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