import Foundation
let pattern = #"(["'])\s*(SELECT)(?:\s+.*)?\s+(FROM)(?:\s+.*)?\1(?:[^\w]|$)"#
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = #"""
SELECT * FROM tbl -- no match - not in a string
"SELECT * FROM tbl" -- matches - in a double-quoted string
'SELECT * FROM tbl;' -- matches - in a single-quoted string
'SELECT * FROM it's -- no match - letter after end quote
"SELECT * FROM tbl' -- no match - quotation marks don't match
'SELECT * FROM tbl" -- no match - quotation marks don't match
"select * from tbl" -- no match - keywords not upper case
'Select * From tbl' -- no match - still not all upper case
"SELECT col1 FROM" -- matches - even though no table name
' SELECT col1 FROM ' -- matches - as above with more whitespace
'SELECT col1, col2 FROM' -- matches - with multiple columns
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let matches = regex.matches(in: testString, range: stringRange)
var result: [[String]] = []
for match in matches {
var groups: [String] = []
for rangeIndex in 1 ..< match.numberOfRanges {
let nsRange = match.range(at: rangeIndex)
guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue }
let string = (testString as NSString).substring(with: nsRange)
groups.append(string)
}
if !groups.isEmpty {
result.append(groups)
}
}
print(result)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression