The like operator is used to match a specified pattern in a string expression. The pattern contains regular characters like %, _
select colA fromtablewhere colA like'P_%'
ILIKE - ILike Operator
The ilike is a case-insensitive operator used to match a specified pattern in a string expression. The pattern contains regular characters like %, _
>select colA fromtablewhere colA ilike 'P_%'>select colA fromtablewhere colA not ilike 'P_%'
RLIKE - RLike Operator
The ilike is a case-insensitive operator used to match a specified pattern in a string expression. The pattern contains regular characters like %, _
>select'E6data' RLIKE 'E[0-9][a-z]+'true
CHARACTER_LENGTH / CHAR_LENGTH / LEN / LENGTH ( <expr> )
Returns the length of a given string expression.
REPLACE( <expr>, <search> [, <replace> ] )
expr - string expression to be searched/modified.
search - string expression to be searched for in the input expression.
replace - optional string expression to be replaced with the search expression. Default is an empty string.
Replaces all instances of search with replace in string expression
TRIM( <expr> )
Trims/removes leading and trailing whitespace in the input string expression.
LTRIM( <expr> )
Removes leading whitespace in the input string expression.
RTRIM( <expr> )
Removes trailing whitespace in the input string expression.
LOWER( <expr> )
Returns the input string expression converted to lowercase characters.
UPPER( <expr> )
Returns the input string expression converted to uppercase characters.
SUBSTRING( <expr>, start, length )
start - numeric expression representing a starting position in the string.
length - numeric expression representing the length of the substring.
Returns a substring from an input string expression of the given length beginning from the start index.