Uso de tablas NESTED con tablas principales y secundarias
Un JOIN se utiliza para combinar filas de dos o más tablas, según una columna relacionada entre ellas. En una tabla jerárquica, la tabla secundaria hereda las columnas de clave primaria de su tabla principal. Esto se realiza de forma implícita, sin incluir las columnas principales en la sentencia CREATE TABLE
del secundario. Todas las tablas de la jerarquía tienen las mismas columnas de clave de partición horizontal.
Puede utilizar la cláusula NESTED TABLES para unir tablas en Oracle NoSQL Database.
Temas relacionados
Descripción general de NESTED TABLES
Note:
Semánticamente, una cláusula NESTED TABLES equivale a una serie de operaciones de unión externa izquierda "centradas" en la tabla de destino.- Consulta varias tablas de la misma jerarquía
- No es un estándar ANSI-SQL
- Soporta la unión de tablas hermanas
Tabla - Tablas anidadas frente a LOJ
Tablas Anidadas | LOJ |
---|---|
Consulta varias tablas de la misma jerarquía | Consulta varias tablas de la misma jerarquía |
No es un estándar ANSI-SQL | Estándar ANSI-SQL |
Soporta la unión de tablas hermanas | No soporta uniones de tablas hermanas |
Si desea seguir los ejemplos, descargue la secuencia de comandos parentchildtbls_loaddata.sql y ejecútela como se muestra a continuación. Este script crea la tabla utilizada en el ejemplo y carga datos en la tabla.
java -jar lib/kvstore.jar kvlite -secure-config disable
java -jar lib/sql.jar -helper-hosts localhost:5000 -store kvstore
parentchildtbls_loaddata.sql
contiene lo siguiente:### Begin Script ###
load -file parentchild.ddl
import -table ticket -file ticket.json
import -table ticket.bagInfo -file bagInfo.json
import -table ticket.passengerInfo -file passengerInfo.json
import -table ticket.bagInfo.flightLegs -file flightLegs.json
### End Script ###
load
, ejecute el script.load -file parentchildtbls_loaddata.sql
### CREATE table ticket if not present ###
CREATE TABLE IF NOT EXISTS ticket(ticketNo LONG,
confNo STRING,
PRIMARY KEY(ticketNo));
### CREATE table ticket.baginfo if not present ###
CREATE TABLE IF NOT EXISTS ticket.bagInfo(id LONG,tagNum LONG,routing STRING,
lastActionCode STRING,
lastActionDesc STRING,
lastSeenStation STRING,
lastSeenTimeGmt TIMESTAMP(4),
bagArrivalDate TIMESTAMP(4), PRIMARY KEY(id));
### CREATE table ticket.bagInfo.flightLegs if not present ###
CREATE TABLE IF NOT EXISTS ticket.bagInfo.flightLegs(flightNo STRING,
flightDate TIMESTAMP(4),
fltRouteSrc STRING,
fltRouteDest STRING,
estimatedArrival TIMESTAMP(4),
actions JSON, PRIMARY KEY(flightNo));
### CREATE table ticket.passengerInfo if not present ###
CREATE TABLE IF NOT EXISTS ticket.passengerInfo(contactPhone STRING,
fullName STRING,
gender STRING, PRIMARY KEY(contactPhone));
Consulte Creación de tablas singleton: modo de entrada de DDL avanzado para conocer los pasos para crear una tabla con una sentencia DDL.
Para cargar datos en la tabla creada desde la consola de OCI, haga clic en el nombre de la tabla. Se muestran los detalles de la tabla. Haga clic en Cargar datos. Haga clic en Seleccionar archivo para cargar y proporcione el archivo JSON que se va a cargar. Puede descargar los archivos DDL y JSON para las tablas principales secundarias aquí.
Ejemplos con tablas anidadas
-
ticket
ticketNo LONG confNo STRING PRIMARY KEY(ticketNo)
-
ticket.bagInfo
id LONG tagNum LONG routing STRING lastActionCode STRING lastActionDesc STRING lastSeenStation STRING, lastSeenTimeGmt TIMESTAMP(4) bagArrivalDate TIMESTAMP(4) PRIMARY KEY(id)
-
ticket.bagInfo.flightLegs
flightNo STRING flightDate TIMESTAMP(4) fltRouteSrc STRING fltRouteDest STRING estimatedArrival TIMESTAMP(4), actions JSON PRIMARY KEY(flightNo)
-
ticket.passengerInfo
contactPhone STRING fullName STRING gender STRING PRIMARY KEY(contactPhone)
Ejemplos SQL
SELECT fullname, contactPhone, gender
FROM NESTED TABLES
(ticket a descendants(ticket.passengerInfo b))
Explicación: este es un ejemplo de una unión en la que la tabla de destino ticket
se une con su tabla secundaria passengerInfo
.
{"fullname":"Elane Lemons","contactPhone":"600-918-8404","gender":"F"}
{"fullname":"Adelaide Willard","contactPhone":"421-272-8082","gender":"M"}
{"fullname":"Dierdre Amador","contactPhone":"165-742-5715","gender":"M"}
{"fullname":"Doris Martin","contactPhone":"289-564-3497","gender":"F"}
{"fullname":"Adam Phillips","contactPhone":"893-324-1064","gender":"M"}
SELECT fullname, contactPhone, gender
FROM NESTED TABLES
(ticket a descendants(ticket.passengerInfo b))
WHERE a.ticketNo=1762324912391
Explicación: este es un ejemplo de una unión donde la tabla de destino ticket
se une con su tabla secundaria passengerInfo
. Además, puede limitar el juego de resultados aplicando una condición de filtro al resultado de la unión. Está limitando el resultado a un número de ticket determinado.
{"fullname":"Elane Lemons","contactPhone":"600-918-8404","gender":"F"}
SELECT * FROM NESTED TABLES
(ticket a descendants(ticket.bagInfo b))
Explicación: este es un ejemplo de una unión en la que la tabla de destino ticket
se une con su tabla secundaria bagInfo
.
{"a":{"ticketNo":1762344493810,"confNo":"LE6J4Z"},
"b":{"ticketNo":1762344493810,"id":79039899165297,"tagNum":17657806255240,"routing":"MIA/LAX/MEL",
"lastActionCode":"OFFLOAD","lastActionDesc":"OFFLOAD","lastSeenStation":"MEL",
"lastSeenTimeGmt":"2019-02-01T16:13:00.0000Z","bagArrivalDate":"2019-02-01T16:13:00.0000Z"}}
{"a":{"ticketNo":1762324912391,"confNo":"LN0C8R"},
"b":{"ticketNo":1762324912391,"id":79039899168383,"tagNum":1765780623244,"routing":"MXP/CDG/SLC/BZN",
"lastActionCode":"OFFLOAD","lastActionDesc":"OFFLOAD","lastSeenStation":"BZN",
"lastSeenTimeGmt":"2019-03-15T10:13:00.0000Z","bagArrivalDate":"2019-03-15T10:13:00.0000Z"}}
{"a":{"ticketNo":1762392135540,"confNo":"DN3I4Q"},
"b":{"ticketNo":1762392135540,"id":79039899156435,"tagNum":17657806224224,"routing":"GRU/ORD/SEA",
"lastActionCode":"OFFLOAD","lastActionDesc":"OFFLOAD","lastSeenStation":"SEA",
"lastSeenTimeGmt":"2019-02-15T21:21:00.0000Z","bagArrivalDate":"2019-02-15T21:21:00.0000Z"}}
{"a":{"ticketNo":1762376407826,"confNo":"ZG8Z5N"},
"b":{"ticketNo":1762376407826,"id":7903989918469,"tagNum":17657806240229,"routing":"JFK/MAD",
"lastActionCode":"OFFLOAD","lastActionDesc":"OFFLOAD","lastSeenStation":"MAD",
"lastSeenTimeGmt":"2019-03-07T13:51:00.0000Z","bagArrivalDate":"2019-03-07T13:51:00.0000Z"}}
{"a":{"ticketNo":1762355527825,"confNo":"HJ4J4P"},
"b":{"ticketNo":1762355527825,"id":79039899197492,"tagNum":17657806232501,"routing":"BZN/SEA/CDG/MXP",
"lastActionCode":"OFFLOAD","lastActionDesc":"OFFLOAD","lastSeenStation":"MXP",
"lastSeenTimeGmt":"2019-03-22T10:17:00.0000Z","bagArrivalDate":"2019-03-22T10:17:00.0000Z"}}
SELECT * FROM
NESTED TABLES (ticket a descendants(ticket.bagInfo b))
WHERE a.ticketNo=1762324912391
Explicación: este es un ejemplo de una unión donde la tabla de destino ticket
se une con su tabla secundaria bagInfo
. Además, puede limitar el juego de resultados aplicando una condición de filtro al resultado de la unión. Está limitando el resultado a un número de ticket determinado.
{"a":{"ticketNo":1762324912391,"confNo":"LN0C8R"},
"b":{"ticketNo":1762324912391,"id":79039899168383,"tagNum":1765780623244,"routing":"MXP/CDG/SLC/BZN",
"lastActionCode":"OFFLOAD","lastActionDesc":"OFFLOAD","lastSeenStation":"BZN",
"lastSeenTimeGmt":"2019-03-15T10:13:00.0000Z","bagArrivalDate":"2019-03-15T10:13:00.0000Z"}}
Note:
Si mueve la restricción de predicado no de unión a la cláusula ON, el juego de resultados incluye todas las filas que cumplen la condición de la cláusula ON. Las filas de la tabla externa derecha que no cumplen la condición ON se rellenan con valores NULL, como se muestra a continuación.SELECT * FROM
NESTED TABLES(ticket a descendants(ticket.bagInfo b
ON a.ticketNo=b.ticketNo
AND a.ticketNo=1762324912391))
{"a":{"ticketNo":1762355527825,"confNo":"HJ4J4P"},"b":null}
{"a":{"ticketNo":1762344493810,"confNo":"LE6J4Z"},"b":null}
{"a":{"ticketNo":1762324912391,"confNo":"LN0C8R"}, "b":{"ticketNo":1762324912391,"id":79039899168383,"tagNum":1765780623244,"routing":"MXP/CDG/SLC/BZN",
"lastActionCode":"OFFLOAD","lastActionDesc":"OFFLOAD","lastSeenStation":"BZN",
"lastSeenTimeGmt":"2019-03-15T10:13:00.0000Z","bagArrivalDate":"2019-03-15T10:13:00.0000Z"}}
{"a":{"ticketNo":1762392135540,"confNo":"DN3I4Q"},"b":null}
{"a":{"ticketNo":1762376407826,"confNo":"ZG8Z5N"},"b":null}
SELECT * FROM
NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b))
Explicación: este es un ejemplo de una unión donde la tabla de destino ticket
se une con su descendiente bagInfo
. Una tabla descendente puede ser cualquier nivel jerárquicamente debajo de una tabla (por ejemplo, fightLegs
es el secundario de bagInfo
, que es el secundario de ticket
, por lo que flightLegs
es un descendiente de ticket
). Se recuperarán todas las filas de la tabla ticket
. Si alguna fila de la tabla ticket
no tiene una fila coincidente en la tabla flightLegs
, se mostrarán valores NULL para esas filas de la tabla flightLegs
.
{"a":{"ticketNo":1762344493810,"confNo":"LE6J4Z"},
"b":{"ticketNo":1762344493810,"id":79039899165297,"flightNo":"BM604","flightDate":"2019-02-01T06:00:00.0000Z",
"fltRouteSrc":"MIA","fltRouteDest":"LAX","estimatedArrival":"2019-02-01T11:00:00.0000Z",
"actions":[{"actionAt":"MIA","actionCode":"ONLOAD to LAX","actionTime":"2019-02-01T06:13:00Z"},
{"actionAt":"MIA","actionCode":"BagTag Scan at MIA","actionTime":"2019-02-01T05:47:00Z"},
{"actionAt":"MIA","actionCode":"Checkin at MIA","actionTime":"2019-02-01T04:38:00Z"}]}}
{"a":{"ticketNo":1762344493810,"confNo":"LE6J4Z"},
"b":{"ticketNo":1762344493810,"id":79039899165297,"flightNo":"BM667","flightDate":"2019-02-01T06:13:00.0000Z",
"fltRouteSrc":"LAX","fltRouteDest":"MEL","estimatedArrival":"2019-02-01T16:15:00.0000Z",
"actions":[{"actionAt":"MEL","actionCode":"Offload to Carousel at MEL","actionTime":"2019-02-01T16:15:00Z"},
{"actionAt":"LAX","actionCode":"ONLOAD to MEL","actionTime":"2019-02-01T15:35:00Z"},
{"actionAt":"LAX","actionCode":"OFFLOAD from LAX","actionTime":"2019-02-01T15:18:00Z"}]}}
{"a":{"ticketNo":1762324912391,"confNo":"LN0C8R"},
"b":{"ticketNo":1762324912391,"id":79039899168383,"flightNo":"BM170","flightDate":"2019-03-15T08:13:00.0000Z",
"fltRouteSrc":"SLC","fltRouteDest":"BZN","estimatedArrival":"2019-03-15T10:14:00.0000Z",
"actions":[{"actionAt":"BZN","actionCode":"Offload to Carousel at BZN","actionTime":"2019-03-15T10:13:00Z"},
{"actionAt":"SLC","actionCode":"ONLOAD to BZN","actionTime":"2019-03-15T10:06:00Z"},
{"actionAt":"SLC","actionCode":"OFFLOAD from SLC","actionTime":"2019-03-15T09:59:00Z"}]}}
{"a":{"ticketNo":1762324912391,"confNo":"LN0C8R"},
"b":{"ticketNo":1762324912391,"id":79039899168383,"flightNo":"BM490","flightDate":"2019-03-15T08:13:00.0000Z",
"fltRouteSrc":"CDG","fltRouteDest":"SLC","estimatedArrival":"2019-03-15T10:14:00.0000Z",
"actions":[{"actionAt":"CDG","actionCode":"ONLOAD to SLC","actionTime":"2019-03-15T09:42:00Z"},
{"actionAt":"CDG","actionCode":"BagTag Scan at CDG","actionTime":"2019-03-15T09:17:00Z"},
{"actionAt":"CDG","actionCode":"OFFLOAD from CDG","actionTime":"2019-03-15T09:19:00Z"}]}}
{"a":{"ticketNo":1762324912391,"confNo":"LN0C8R"},
"b":{"ticketNo":1762324912391,"id":79039899168383,"flightNo":"BM936","flightDate":"2019-03-15T08:00:00.0000Z",
"fltRouteSrc":"MXP","fltRouteDest":"CDG","estimatedArrival":"2019-03-15T09:00:00.0000Z",
"actions":[{"actionAt":"MXP","actionCode":"ONLOAD to CDG","actionTime":"2019-03-15T08:13:00Z"},
{"actionAt":"MXP","actionCode":"BagTag Scan at MXP","actionTime":"2019-03-15T07:48:00Z"},
{"actionAt":"MXP","actionCode":"Checkin at MXP","actionTime":"2019-03-15T07:38:00Z"}]}}
{"a":{"ticketNo":1762392135540,"confNo":"DN3I4Q"},
"b":{"ticketNo":1762392135540,"id":79039899156435,"flightNo":"BM79","flightDate":"2019-02-15T01:00:00.0000Z",
"fltRouteSrc":"GRU","fltRouteDest":"ORD","estimatedArrival":"2019-02-15T11:00:00.0000Z",
"actions":[{"actionAt":"GRU","actionCode":"ONLOAD to ORD","actionTime":"2019-02-15T01:21:00Z"},
{"actionAt":"GRU","actionCode":"BagTag Scan at GRU","actionTime":"2019-02-15T00:55:00Z"},
{"actionAt":"GRU","actionCode":"Checkin at GRU","actionTime":"2019-02-14T23:49:00Z"}]}}
{"a":{"ticketNo":1762392135540,"confNo":"DN3I4Q"}
,"b":{"ticketNo":1762392135540,"id":79039899156435,"flightNo":"BM907","flightDate":"2019-02-15T01:21:00.0000Z",
"fltRouteSrc":"ORD","fltRouteDest":"SEA","estimatedArrival":"2019-02-15T21:22:00.0000Z",
"actions":[{"actionAt":"SEA","actionCode":"Offload to Carousel at SEA","actionTime":"2019-02-15T21:16:00Z"},
{"actionAt":"ORD","actionCode":"ONLOAD to SEA","actionTime":"2019-02-15T20:52:00Z"},
{"actionAt":"ORD","actionCode":"OFFLOAD from ORD","actionTime":"2019-02-15T20:44:00Z"}]}}
{"a":{"ticketNo":1762376407826,"confNo":"ZG8Z5N"},
"b":{"ticketNo":1762376407826,"id":7903989918469,"flightNo":"BM495","flightDate":"2019-03-07T07:00:00.0000Z",
"fltRouteSrc":"JFK","fltRouteDest":"MAD","estimatedArrival":"2019-03-07T14:00:00.0000Z",
"actions":[{"actionAt":"MAD","actionCode":"Offload to Carousel at MAD","actionTime":"2019-03-07T13:54:00Z"},
{"actionAt":"JFK","actionCode":"ONLOAD to MAD","actionTime":"2019-03-07T07:00:00Z"},
{"actionAt":"JFK","actionCode":"BagTag Scan at JFK","actionTime":"2019-03-07T06:53:00Z"},
{"actionAt":"JFK","actionCode":"Checkin at JFK","actionTime":"2019-03-07T05:03:00Z"}]}}
{"a":{"ticketNo":1762355527825,"confNo":"HJ4J4P"},
"b":{"ticketNo":1762355527825,"id":79039899197492,"flightNo":"BM386","flightDate":"2019-03-22T07:23:00.0000Z",
"fltRouteSrc":"CDG","fltRouteDest":"MXP","estimatedArrival":"2019-03-22T10:24:00.0000Z",
"actions":[{"actionAt":"MXP","actionCode":"Offload to Carousel at MXP","actionTime":"2019-03-22T10:15:00Z"},
{"actionAt":"CDG","actionCode":"ONLOAD to MXP","actionTime":"2019-03-22T10:09:00Z"},
{"actionAt":"CDG","actionCode":"OFFLOAD from CDG","actionTime":"2019-03-22T10:01:00Z"}]}}
{"a":{"ticketNo":1762355527825,"confNo":"HJ4J4P"},
"b":{"ticketNo":1762355527825,"id":79039899197492,"flightNo":"BM578","flightDate":"2019-03-22T07:23:00.0000Z",
"fltRouteSrc":"SEA","fltRouteDest":"CDG","estimatedArrival":"2019-03-21T23:24:00.0000Z",
"actions":[{"actionAt":"SEA","actionCode":"ONLOAD to CDG","actionTime":"2019-03-22T11:26:00Z"},
{"actionAt":"SEA","actionCode":"BagTag Scan at SEA","actionTime":"2019-03-22T10:57:00Z"},
{"actionAt":"SEA","actionCode":"OFFLOAD from SEA","actionTime":"2019-03-22T11:07:00Z"}]}}
{"a":{"ticketNo":1762355527825,"confNo":"HJ4J4P"},
"b":{"ticketNo":1762355527825,"id":79039899197492,"flightNo":"BM704","flightDate":"2019-03-22T07:00:00.0000Z",
"fltRouteSrc":"BZN","fltRouteDest":"SEA","estimatedArrival":"2019-03-22T09:00:00.0000Z",
"actions":[{"actionAt":"BZN","actionCode":"ONLOAD to SEA","actionTime":"2019-03-22T07:23:00Z"},
{"actionAt":"BZN","actionCode":"BagTag Scan at BZN","actionTime":"2019-03-22T06:58:00Z"},
{"actionAt":"BZN","actionCode":"Checkin at BZN","actionTime":"2019-03-22T05:20:00Z"}]}}
SELECT * FROM
NESTED TABLES (ticket.bagInfo.flightLegs b ancestors(ticket a))
WHERE a.ticketNo=1762344493810
Explicación: este es un ejemplo de una unión donde la tabla de destinoticket
se une con su descendiente bagInfo
. Además, puede limitar el juego de resultados aplicando una condición de filtro al resultado de la unión. Está limitando el resultado a un número de ticket determinado.
El resultado tiene dos filas, lo que implica que hay dos tramos de vuelo para este número de billete.
"a":{"ticketNo":1762344493810,"confNo":"LE6J4Z"},
"b":{"ticketNo":1762344493810,"id":79039899165297,"flightNo":"BM604",
"flightDate":"2019-02-01T06:00:00.0000Z","fltRouteSrc":"MIA","fltRouteDest":"LAX",
"estimatedArrival":"2019-02-01T11:00:00.0000Z",
"actions":[{"actionAt":"MIA","actionCode":"ONLOAD to LAX","actionTime":"2019-02-01T06:13:00Z"},
{"actionAt":"MIA","actionCode":"BagTag Scan at MIA","actionTime":"2019-02-01T05:47:00Z"},
{"actionAt":"MIA","actionCode":"Checkin at MIA","actionTime":"2019-02-01T04:38:00Z"}]}}
{"a":{"ticketNo":1762344493810,"confNo":"LE6J4Z"},
"b":{"ticketNo":1762344493810,"id":79039899165297,"flightNo":"BM667",
"flightDate":"2019-02-01T06:13:00.0000Z","fltRouteSrc":"LAX","fltRouteDest":"MEL",
"estimatedArrival":"2019-02-01T16:15:00.0000Z",
"actions":[{"actionAt":"MEL","actionCode":"Offload to Carousel at MEL","actionTime":"2019-02-01T16:15:00Z"},
{"actionAt":"LAX","actionCode":"ONLOAD to MEL","actionTime":"2019-02-01T15:35:00Z"},
{"actionAt":"LAX","actionCode":"OFFLOAD from LAX","actionTime":"2019-02-01T15:18:00Z"}]}}
SELECT b.id,count(*) AS NUMBER_HOPS
FROM NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b))
GROUP BY b.id
Explicación: agrupa los datos según el ID de bolsa (mediante GROUP BY) y obtiene el recuento de tramos de vuelo (mediante count()) para cada bolsa.
{"id":79039899168383,"NUMBER_HOPS":3}
{"id":79039899156435,"NUMBER_HOPS":2}
{"id":7903989918469,"NUMBER_HOPS":1}
{"id":79039899165297,"NUMBER_HOPS":2}
{"id":79039899197492,"NUMBER_HOPS":3}
SELECT b.id,count(*) AS NUMBER_HOPS FROM
NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b))
WHERE a.ticketNo=1762355527825
GROUP BY b.id
Explicación: se agrupan los datos según el ID de bolsa (mediante GROUP BY) y se obtiene el recuento de tramos de vuelo (mediante count()) para cada bolsa. Además, puede filtrar los resultados de un número de ticket concreto.
{"id":79039899197492,"NUMBER_HOPS":3}
SELECT b.id, routing FROM
NESTED TABLES(ticket a descendants(ticket.bagInfo b))
WHERE CAST (b.bagArrivalDate AS Timestamp(0))>=
CAST ("2019-01-01T00:00:00" AS Timestamp(0))
Explicación: este es un ejemplo de una unión en la que la tabla de destinoticket
se une con su tabla secundaria bagInfo
. La condición de filtro se aplica en bagArrivalDate
. La función CAST
se utiliza para convertir la cadena en un registro de hora y, a continuación, se comparan los valores.
{"id":79039899197492,"routing":"BZN/SEA/CDG/MXP"}
{"id":79039899165297,"routing":"MIA/LAX/MEL"}
{"id":79039899168383,"routing":"MXP/CDG/SLC/BZN"}
{"id":79039899156435,"routing":"GRU/ORD/SEA"}
{"id":7903989918469,"routing":"JFK/MAD"}
Ejemplos de API de Consulta
Para ejecutar la consulta, utilice la API NoSQLHandle.query()
.
/* fetch rows based on joins*/
private static void fetchRows(NoSQLHandle handle,String sql_stmt) throws Exception {
try (
QueryRequest queryRequest = new QueryRequest().setStatement(sql_stmt);
QueryIterableResult results = handle.queryIterable(queryRequest)) {
System.out.println("Query results:");
for (MapValue res : results) {
System.out.println("\t" + res);
}
}
}
System.out.println("Fetching data using NESTED TABLES:");
String sql_stmt_nt ="SELECT * FROM NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b))";
/* fetching rows using nested tables*/
fetchRows(handle,sql_stmt_nt);
Para ejecutar la consulta, utilice el método borneo.NoSQLHandle.query()
.
# Fetch data from the table based on joins
def fetch_data(handle,sqlstmt):
request = QueryRequest().set_statement(sqlstmt)
print('Query results for: ' + sqlstmt)
result = handle.query(request)
for r in result.get_results():
print('\t' + str(r))
sql_stmt_nt='SELECT * FROM NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b))'
print('Fetching data using NESTED TABLES ')
fetch_data(handle,sql_stmt_nt)
Para ejecutar una consulta, utilice la función Client.Query
.
func fetchData(client *nosqldb.Client, err error,
tableName string, querystmt string)(){
prepReq := &nosqldb.PrepareRequest{ Statement: querystmt,}
prepRes, err := client.Prepare(prepReq)
if err != nil {
fmt.Printf("Prepare failed: %v\n", err)
return
}
queryReq := &nosqldb.QueryRequest{
PreparedStatement: &prepRes.PreparedStatement,}
var results []*types.MapValue
for {
queryRes, err := client.Query(queryReq)
if err != nil {
fmt.Printf("Query failed: %v\n", err)
return
}
res, err := queryRes.GetResults()
if err != nil {
fmt.Printf("GetResults() failed: %v\n", err)
return
}
results = append(results, res...)
if queryReq.IsDone() {
break
}
}
for i, r := range results {
fmt.Printf("\t%d: %s\n", i+1,
jsonutil.AsJSON(r.Map()))
}
}
querystmt_nt:= "SELECT * FROM NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b)"
fmt.Println("Fetching data using NESTED TABLES")
fetchData(client, err,querystmt_nt)
Para ejecutar una consulta, utilice el método query
.
//fetches data from the table
async function fetchData(handle,querystmt) {
const opt = {};
try {
do {
const result = await handle.query(querystmt, opt);
for(let row of result.rows) {
console.log(' %O', row);
}
opt.continuationKey = result.continuationKey;
} while(opt.continuationKey);
} catch(error) {
console.error(' Error: ' + error.message);
}
}
const stmt_nt = 'SELECT * FROM NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b))';
console.log("Fetching data using NESTED TABLES");
await fetchData(handle,stmt_nt);
interface StreamInt {
acct_Id: Integer;
profile_name: String;
account_expiry: TIMESTAMP;
acct_data: JSON;
}
/* fetches data from the table */
async function fetchData(handle: NoSQLClient,querystmt: string) {
const opt = {};
try {
do {
const result = await handle.query<StreamInt>(querystmt, opt);
for(let row of result.rows) {
console.log(' %O', row);
}
opt.continuationKey = result.continuationKey;
} while(opt.continuationKey);
} catch(error) {
console.error(' Error: ' + error.message);
}
}
const stmt_nt = 'SELECT * FROM NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b))';
console.log("Fetching data using NESTED TABLES");
await fetchData(handle,stmt_nt);
Para ejecutar una consulta, puede llamar al método QueryAsync
o llamar al método GetQueryAsyncEnumerable
e iterar sobre el elemento enumerable asíncrono resultante.
private static async Task fetchData(NoSQLClient client,String querystmt){
var queryEnumerable = client.GetQueryAsyncEnumerable(querystmt);
await DoQuery(queryEnumerable);
}
private static async Task DoQuery(IAsyncEnumerable<QueryResult<RecordValue>> queryEnumerable){
Console.WriteLine(" Query results:");
await foreach (var result in queryEnumerable) {
foreach (var row in result.Row
{
Console.WriteLine();
Console.WriteLine(row.ToJsonString());
}
}
}
private const string stmt_nt ="SELECT * FROM NESTED TABLES (ticket a descendants(ticket.bagInfo.flightLegs b))";
Console.WriteLine("Fetching data using NESTED TABLES: ");
await fetchData(client,stmt_nt);