import Foundation
let pattern = #".*?(WHERE.*?)(GROUP BY|;|\n)"#
let regex = try! NSRegularExpression(pattern: pattern, options: .dotMatchesLineSeparators)
let testString = #"""
s = '''FROM clinics INNER JOIN clinic_drug on clinics.clinicId = clinic_drug.clinicId
WHERE clinic_drug.amount = 0
GROUP BY clinics.name;'''
s = '''FROM clinics INNER JOIN clinic_drug on clinics.clinicId = clinic_drug.clinicId
WHERE clinic_drug.amount = 2
GROUP BY clinics.name;'''
s = '''FROM clinics INNER JOIN clinic_drug on clinics.clinicId = clinic_drug.clinicId
WHERE clinic_drug.amount = 3;
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$1\n"#
let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString)
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