SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 2) Function JSONExtract (alias a) (children 1) ExpressionList (children 3) Literal \'{"a":1234567890123456789}\' Literal \'a\' Literal \'UInt64\' Function toTypeName (children 1) ExpressionList (children 1) Identifier a