com.orchestranetworks.query

Interface QueryBuilder

public interface QueryBuilder

A builder for query objects, capable of creating queries which reference tables from multiple datasets.

The same builder can be used to create multiple queries.

Examples

The following query involves a single dataset:

 
        Query<Tuple> query = dataset.createQuery("SELECT * FROM customer");
 
 

The following query involves a join between two datasets, where dataset0 is the default dataset and dataset1 is named s1:

 
        QueryBuilder builder = dataset0.createQueryBuilder().addDataset("s1", dataset1);
        Query<Tuple> query = builder
                .build("SELECT t1.c_custkey, t2.o_orderkey " +
                        "FROM customer t1 " +
                        "INNER JOIN s1.orders t2 " +
                        "  ON t1.c_custkey=t2.o_custkey.c_custkey ");
 
 

The default dataset dataset0 will have the default name _public.

Since:

6.0.0

See Also:

Adaptation.createQueryBuilder()

Method Summary

Modifier and Type	Method and Description
QueryBuilder	addDataset(String aName, Adaptation aDataset) Adds the specified dataset using the provided name.
Query<Tuple>	build(String aSql) Creates a query from the specified SQL string, whose result will return Tuple objects.
<T> Query<T>	build(String aSql, Class<T> aClass) Creates a query from the specified SQL string, whose result will return objects of the specified type.

Method Detail

addDataset

QueryBuilder addDataset(String aName,
                        Adaptation aDataset)

Adds the specified dataset using the provided name. If this builder previously contained a dataset with the same name, the old value is replaced.

Parameters:

aName - the name under which the dataset is registered.

aDataset - the dataset to be registered.

Returns:

the same builder object, with the result of this method applied. to it.

Throws:

IllegalArgumentException - if there are problems with the dataset, and it cannot be used.

build

Query<Tuple> build(String aSql)

Creates a query from the specified SQL string, whose result will return Tuple objects.

Parameters:

aSql - the SQL string that will be used to create the query object.

Returns:

a structurally valid query object which can be executed.

Throws:

QueryParseException - if the query string is not valid; for example, it contains syntax errors, it references missing tables, missing columns, etc.

build

<T> Query<T> build(String aSql,
                   Class<T> aClass)

Creates a query from the specified SQL string, whose result will return objects of the specified type.

Parameters:

aSql - the SQL string that will be used to create the query object.

Returns:

a structurally valid query object which can be executed.

Throws:

QueryParseException - if the SQL query is not valid; for example, it contains syntax errors, it references missing tables, missing columns, etc.