{
			name: "select-is_not_string",
			input: []byte(`c1,c2,c3
1,2,3
1,,3`),
			query:      `select * from S3object where _2 IS NOT ''`,
			wantResult: `{"c1":"1","c2":"2","c3":"3"}`,
		},
		{
			name: "select-is_not_string",
			input: []byte(`c1,c2,c3
1,2,3
1,,3`),
			query:      `select * from S3object where _2 != '' AND _2 > 1`,
			wantResult: `{"c1":"1","c2":"2","c3":"3"}`,
		},
	}