import Foundation
let pattern = #"(\[\w+)\.(?=\w+])"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"""
I am parsing some SQL statements and have found places where the SELECT statement may be:
SELECT [tblCustomer].[FirstName], [tblCustomer.LastName], [tblOrder].[Order_No]
Another example:
SELECT IIf([tbl_ref_Service].[Root_Service] Is Null,[tbl_ref_Service].[Service],[tbl_ref_Service].[Root_Service]) AS Root_Service, tbl_POC_Assigned.POC_ID, [tbl_POC_Assigned.Hex_ID] & "_" & [tbl_Hex.Generic_ID] & "_" & [tbl_Lateral.Service_ID] & "_" & [tbl_Hex.ODD_Micap] & "_Null" AS Tool_Generic_Line, tbl_Hex.Building_ID AS Hex_Building_ID, tbl_POC.Lateral_ID, tbl_Generic_Service.Peak_Flow, [Diversity_Factor]*[Peak_Flow] AS Avg_Flow, tbl_POC_Assigned.Flow, tbl_POC_Assigned.Flow_Avg
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$1].["#
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