In PostgreSQL, we can use the regexp_like() function to check whether or not a match of a POSIX regular expression occurs within a given string.
We pass the string as the first argument and the pattern as the second argument. We can also provide a flag as an optional third argument, which determines how the function behaves.
Continue readingIn PostgreSQL, we can use the quote_ident() function to quote identifiers in a SQL statement string.
Quotes are only added if necessary. Any embedded quotes are doubled.
Continue readingIn PostgreSQL, the format() function produces output formatted according to a format string. The first argument is the format string (consisting of one or more format specifiers that start with the % character), and the subsequent arguments are the values to format.
If you’re getting an error that reads “function array_shuffle(integer) does not exist” when using the array_shuffle() function in PostgreSQL, it’s probably because the argument you’re passing to the function is not an array.
More specifically, this error message implies that you’re passing an integer. The same error can occur when passing other non-array types (such as numeric), but the solution is the same.
The argument for this function must be an array.
To fix this error, replace the integer value with an array value when calling the array_shuffle() function.
In PostgreSQL, the regexp_instr() function returns the starting or ending position of the N‘th match of a POSIX regular expression pattern to a string. If there’s no match, it returns zero.
We pass the string and pattern as arguments. The function also accepts some optional arguments that allow us to be specific with how the function works.
Continue readingIf you’re getting an error that reads “negative substring length not allowed” when using PostgreSQL’s overlay() function, it’s probably because you’re passing a negative value (or zero) to the FROM argument.
To fix this issue, be sure that the FROM argument is a positive integer.
In PostgreSQL, we can use the substring() function to extract the first substring matching the specified POSIX or SQL regular expression.
In PostgreSQL, the regexp_count() function returns the number of times a given POSIX regular expression pattern matches in a given string.
We pass the string and pattern as arguments. We can also pass an argument to specify where to start the search. Additionally, we also have the option of specifying a flag that changes the function’s behaviour.
Continue readingIn PostgreSQL, we can use the quote_literal() function to quote strings within a SQL statement string.
Any embedded single-quotes and backslashes are properly doubled.
Continue readingIf you’re getting an error that reads “source array too small” when updating an array in PostgreSQL, it’s probably because you’re passing a slice that’s smaller than your specified range. For example, if you specify a range that covers four elements but provide an array that contains just three elements, then you’d get this error.
To fix the error, be sure to provide an an array that contains at least as many elements as are specified in the range.
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