Splits a statement's leading WITH clause into its CTE definitions and the main statement,
using positions in the original text, so every part is returned exactly as written. Leading
comments are skipped. Returns null when the statement does not start with WITH, or when the
clause cannot be read (an unbalanced parenthesis, a missing AS).
Splits a statement's leading
WITHclause into its CTE definitions and the main statement, using positions in the original text, so every part is returned exactly as written. Leading comments are skipped. Returnsnullwhen the statement does not start withWITH, or when the clause cannot be read (an unbalanced parenthesis, a missingAS).