How do you wrap regular expressions in a string?
A string literal in a REGEXP function or condition conforms to the rules for SQL text literals. By default, regular expressions must be enclosed in single quotes. If your regular expression includes the single quote character, enter two single quotes to represent a single quote within the expression.
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How to search for literals in regular expressions?
Literals, which are the characters you’re looking for A regular expression can specify complex patterns of character sequences. For example, the following regular expression matches the literals fo ht, the literal t, the literal p optionally followed by the literal s, and finally the literal colon (:): (f|ht)tps?:
When does a regular expression match a string?
Regular expressions are a notation for describing sets of character strings. When a string is in the set described by a regular expression, we often say that the regular expression matches the string.
When to use conditional in a regular expression?
✽ The conditional (? (1)END|//b) checks if Group 1 has been set (ie if START has matched). If so, the motor must match END. Otherwise, the engine must match a word boundary.
When to use a regular expression in SQL?
The trick is to define when the expression ends. The regular expression above begins the match with two hyphens that continue until a return character and a newline character are encountered. Since the comment ends with a line feed, we tell the expression to continue matching until we find a return character and a newline character [^].
How are characters specified in a regular expression?
A regular expression is specified by the following types of characters: Metacharacters, which are operators that specify search algorithms Literals, which are the characters you are looking for A regular expression can specify complex patterns of character sequences.