CreateQuery test_prewhere_column_type (children 3)
 Identifier test_prewhere_column_type
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration a (children 1)
    DataType LowCardinality (children 1)
     ExpressionList (children 1)
      DataType String
   ColumnDeclaration x (children 1)
    DataType Nullable (children 1)
     ExpressionList (children 1)
      DataType Int32
 Storage definition (children 2)
  Function MergeTree
  Function tuple (children 1)
   ExpressionList