SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 2) Function JSONExtract (alias a) (children 1) ExpressionList (children 3) Literal \'{"a":"1234567899999"}\' Literal \'a\' Literal \'UInt32\' Function toTypeName (children 1) ExpressionList (children 1) Identifier a