SQL Server daily accumulation (ii)

1. The LIKE operator: compares a string expression to a pattern in an SQL expression.

Syntax: expression like ' pattern ', expression is a match field, pattern is a matching string. You can find field values that match the pattern you specify by using the LIKE operator. For pattern, you can specify a full value (for example Like "Smith" ), or you can use wildcards to find values within a range (for example Like "Sm*" ).

The following table shows how you can use like to test expressions for different patterns.

match type	< Strong class= "bterm" > mode	match (return )	no match (return )
Multiple characters	A*a or A%a	AA, ABa, Abbba	Abc
	*ab* or%ab%	ABC, AABB, Xab	Azb, BAC
Special characters	A[*]a	A*a	Aaa
Multiple characters	ab* or ab%	ABCDEFG, ABC	Cab, AAB
Single character	A?a or A_a	AAA, A3A, ABa	Abbba
Single digit	A#a	a0a, A1A, A2A	AAA, A10A
Character Range	[A-z]	F, P, J	2, &
Outside the range	[!a-z]	9, &,%	B, a
Non-numeric value	[!0-9]	A, a, &, ~	0, 1, 9
Composite values	a[!b-m]#	An9, Az0, A99	ABC, AJ0

wildcard characters that can be used with the LIKE operator, such as the following table:

pattern the characters in	matches in expression
? Or _ (underline)	Any single character
Or	0 or more characters
#	Any single number (0-9)
[Charlist]	Any single character in the charlist.
[!charlist]	Any single character that is not in the charlist.

SQL Server daily accumulation (ii)