An sql_string contains a single-quoted string. Single quote characters that are located inside a string are doubled and strings that are already single-quoted are double-quoted before being placed within another pair of single quotes.
Examples:
String to pass | sql_string |
my string | 'my string' |
string with ' inside it | 'string with ' ' inside it' |
'string already in quotes' | ' ' 'string already in quotes' ' ' |