I am going to bring closure to my series of very short articles or tidbits on Transaction SQL Operators. An operator is a symbol specifying an action that is performed on one or more expressions. <\/p>\n
I will exploring the operator precedence<\/a> today. In mathematics and computer programming, the order of operations<\/a> is a set of rules used to clarify which procedures should be performed first in a given mathematical expression.<\/p>\n I do not have enough time in this very short article to go over the eight levels that group and order expression evaluation. However, I want to go over one example in which parentheses can be used to change the order of evaluation.<\/p>\n The first expression evaluates multiplication first since it is considered a higher level than subtraction. The second example changes the order by using parentheses.<\/p>\n The example script below explores all three operators.<\/p>\n The output of the above TSQL statements is listed below. <\/p>\n\r\n--\r\n-- Operator Precedence\r\n--\r\n\r\n-- Results in 2\r\nselect x = 2*3-2*2;\r\n\r\n-- Results in 4\r\nselect 2*(3-2)*2 as y;\r\n\r\n<\/pre>\n
\r\n-- ~ OUTPUT ~\r\nx\r\n-----------\r\n2\r\n\r\ny\r\n-----------\r\n4\r\n\r\n<\/pre>\n<\/p>\n