Joe Celko, in Joe Celko's SQL for Smarties (Fifth Edition), 2015 14.6 Math and NULLs Another problem is that a matrix has rows and columns that are not the same as the rows and columns of an SQL table as you read the rest of this section, be careful not to confuse the two. The presence of NULLs is not defined in linear algebra and I have no desire to invent a three-valued linear algebra of my own. Let us assume that we have two-dimensional arrays that are declared as tables, using two columns for subscripts, and that all columns are declared with a NOT NULL constraint. SQL was never meant to be a language for calculations. Though it is possible to do many matrix operations in SQL, it is not a good idea, because such queries and operations will eat up resources and run much too long. You can find that information in a college freshman algebra book. Matrices are mathematical structures with particular properties that we cannot take the time to discuss here.

Joe Celko, in Joe Celko's SQL for Smarties (Fourth Edition), 2011 33.3 Matrix Operations in SQLĪ matrix is not quite the same thing as an array. The NULL in SQL is the one way of handling missing values and since host languages do not support NULLs, the programmer can either replace them with another value that is expressible in the host language or use INDICATOR variables to signal the host program to take special actions for them. SQL may also have a TINYINT exact numeric type with a range of 0 to 255 where for every numeric type, the least value is less than zero and the greatest value is greater than zero. Likewise, BIGINT has a scale of zero, but the range of values it can hold are greater than or equal to the range that INTEGER can hold in the implementation. SMALLINT has a scale of zero, but the range of values it can hold are less than or equal to the range that INTEGER can hold in the implementation. An integer has a scale of zero, but the syntax simply uses the word INTEGER or the abbreviation INT. The data types NUMERIC, DECIMAL, INTEGER, BIGINT, and SMALLINT are exact numeric types. The precision is a positive integer that determines the number of significant digits in a particular radix. An exact numeric value has a precision and a scale.

Numbers in SQL are classified as either exact or approximate. This chapter focuses on the various numeric data types used in SQL.

Joe Celko, in Joe Celko's SQL for Smarties (Fourth Edition), 2011 Publisher Summary

Numeric meaning