Union [/union]
Union [POST]
It makes a union between two members, both could be a table, join or union, evaluated in a recursive way. It takes a few parameters which identify
the data source keyspace and tablename. Other optional parameters are aimed to apply DML functionality: groupby, select, calculated, etc.
- left operand: table description, join description or union description
- right operand: table description, join description or union description
| Possible combinations | ||
|---|---|---|
| table_a | ∪ | table_b |
| table_a | ∪ | join_b |
| table_a | ∪ | union_b |
| join_a | ∪ | table_b |
| join_a | ∪ | join_b |
| join_a | ∪ | union_b |
| union_a | ∪ | table_b |
| union_a | ∪ | join_b |
| union_a | ∪ | union_b |
-
Select
Projection operation of relational algebra. It allows rename operation as well.
"select": [<field_a>, <field_b>, {<field_c>: <field_c_renamed>}, ... ], -
Calculated
Optional parameter that allows Spark SQL expressions which calculate new fields from others.
"calculated": { <calculated_field>: <Spark SQL expression> }, -
Filter
Filter expression
"filter": <filter_expression>, -
Group by
Apply a
groupbystatement over two members grouped."groupby": { "grouped": [<field_a>], "agg": { "count": [<field_b>] } } -
Sort by
"sortby": [ {<field_a>: "desc"}, {<field_b>: "asc"}, //default ... ] -
Save
It writes back results into Cassandra existing table. The result set must be compatible with Cassandra table structure but as flexible as Cassandra is.
"save": { "keyspace": <destination keyspace>, "tablename": <destination table> } -
Shell snippet
curl --request POST \
--url http://localhost:5000/union \
--header 'content-type: application/json' \
--data ' {
"table_a": {
"keyspace": "examples",
"tablename": "mock_cars",
"select": [],
"filter": "color == \"Blue\""
},
"table_b": {
"keyspace": "examples",
"tablename": "mock_cars",
"select": [],
"filter": "color == \"Red\""
}
}'
// Response 200 OK
{
"calculated": null,
"data": {
"car_id": {
"0": "f52a0f09-0e2d-46b6-b79c-588305afb489",
"1": "33b07a75-2507-4d14-923c-87f8c17e034b",
"2": "70e289f2-935a-4ea7-a4a3-eaa8f2c8ac9b",
"3": "78a5c5bb-89e9-4922-b3a7-3d1444aa0261",
"4": "e6e6a3d4-3283-4adc-ad19-bb00c2d48495",
"5": "d262a903-a259-4533-994c-7f92bd3c53b3",
"6": "a41a2ca1-0a95-470f-aaf7-847cdfe8d828",
"7": "ea355147-0401-4572-b881-b139b8ff6327",
"8": "5acf6fde-56ca-4cd5-b76c-68997081fa2d",
"9": "7150b2f9-5bac-4b27-b5f4-33828bf21253",
"10": "a41e2d2b-404e-4fb9-aff6-1aa65cd85491",
...
"47": "1a8c51d5-a4fb-4f9f-946e-8ab5b0add613",
"48": "e9ffa861-4773-4bc8-865e-bc8a7436cef6",
"49": "86b69f88-2577-4edc-a227-66744ebf3418",
"50": "6025fff5-b649-460c-b55f-3d0d4e449655",
"51": "a94deef3-4185-4cc6-83ab-624c0993e6ca",
"52": "01feb5e1-6b27-4972-b828-b94ddcc55926",
"53": "ea42bc1e-1f55-44cb-b213-ab2af3d582a1",
"54": "e20d1c0e-ad68-4f99-a78e-404511b4a4bb",
"55": "41f8ffae-3de7-41b5-9bb3-1744d7e07d8b",
"56": "4e1c886a-3187-4183-9fe1-83b7bddbdbe3",
"57": "366a369c-b6ae-4e2d-a94e-c92c14f45b20",
...
},
"car_make": {
"0": "Ferrari",
"1": "Acura",
"2": "GMC",
"3": "Mercedes-Benz",
"4": "Subaru",
"5": "Lexus",
"6": "Chevrolet",
"7": "Hyundai",
"8": "Honda",
"9": "Pontiac",
"10": "Maybach",
...
"47": "Mercury",
"48": "Kia",
"49": "Chevrolet",
"50": "Saturn",
"51": "Audi",
"52": "Ford",
"53": "Mitsubishi",
"54": "Chevrolet",
"55": "Toyota",
"56": "Honda",
"57": "Chevrolet",
...
},
"car_model": {
"0": "612 Scaglietti",
"1": "NSX",
"2": "Sonoma",
"3": "G-Class",
"4": "Forester",
"5": "LS Hybrid",
"6": "Avalanche 1500",
"7": "Elantra",
"8": "S2000",
"9": "Safari",
"10": "57S",
...
"47": "Mountaineer",
"48": "Sportage",
"49": "Astro",
"50": "Ion",
"51": "Allroad",
"52": "E350",
"53": "Lancer Evolution",
"54": "Silverado 3500",
"55": "RAV4",
"56": "Prelude",
"57": "Equinox",
...
},
"car_model_year": {
"0": 2006,
"1": 1996,
"2": 1992,
"3": 2006,
"4": 2007,
"5": 2010,
"6": 2005,
"7": 2003,
"8": 2005,
"9": 1989,
"10": 2005,
...
"47": 2003,
"48": 1998,
"49": 2002,
"50": 2003,
"51": 2001,
"52": 2004,
"53": 2003,
"54": 2010,
"55": 2012,
"56": 1994,
"57": 2005,
...
},
"color": {
"0": "Blue",
"1": "Blue",
"2": "Blue",
"3": "Blue",
"4": "Blue",
"5": "Blue",
"6": "Blue",
"7": "Blue",
"8": "Blue",
"9": "Blue",
"10": "Blue",
...
"47": "Red",
"48": "Red",
"49": "Red",
"50": "Red",
"51": "Red",
"52": "Red",
"53": "Red",
"54": "Red",
"55": "Red",
"56": "Red",
"57": "Red",
...
},
"id_owner": {
"0": 52,
"1": 128,
"2": 803,
"3": 241,
"4": 76,
"5": 858,
"6": 486,
"7": 145,
"8": 42,
"9": 877,
"10": 724,
...
"47": 223,
"48": 641,
"49": 450,
"50": 231,
"51": 640,
"52": 624,
"53": 888,
"54": 674,
"55": 578,
"56": 200,
"57": 182,
...
},
"registration": {
"0": "3104-ELC",
"1": "2505-PIM",
"2": "9636-FLX",
"3": "5263-DQS",
"4": "5382-OQM",
"5": "1157-BJE",
"6": "7514-YCT",
"7": "7590-NTT",
"8": "0189-BMC",
"9": "8365-NSW",
"10": "4643-MJO",
...
"46": "6817-SYC",
"47": "3071-PDH",
"48": "9307-YLU",
"49": "2691-RBI",
"50": "7224-BCG",
"51": "1279-NNT",
"52": "4107-TZV",
"53": "1138-SMC",
"54": "0392-VLM",
"55": "3629-GFQ",
"56": "6365-HYN",
"57": "7891-QWU",
}
},
"join_a": null,
"join_b": null,
"join_key": [],
"s_filter": null,
"save": null,
"select": null,
"sortby": null,
"status": 200,
"success": true,
"table_a": {
"filter": "color == \"Blue\"",
"keyspace": "examples",
"select": [],
"tablename": "mock_cars"
},
"table_b": {
"filter": "color == \"Red\"",
"keyspace": "examples",
"select": [],
"tablename": "mock_cars"
},
"union_a": null,
"union_b": null,
"union_groupby": null,
"union_type": "union_all"
}
curl --request POST \
--url http://localhost:5000/union \
--header 'content-type: application/json' \
--data ' {
"table_a": {
"keyspace": "examples",
"tablename": "mock_cars",
"select": [],
"filter": "color == \"Blue\""
},
"union_b": {
"table_a": {
"keyspace": "examples",
"tablename": "mock_cars",
"select": [],
"filter": "color == \"Red\""
},
"table_b": {
"keyspace": "examples",
"tablename": "mock_cars",
"select": [],
"filter": "color == \"Yellow\""
}
}
}'