Package io.ultreia.java4all.util.sql

Class SqlQuery<O>

java.lang.Object

io.ultreia.java4all.util.sql.SqlQuery<O>

Type Parameters:

O - the type of result data

public abstract class SqlQuery<O>
extends Object

Wrap a Sql query some object.

Implements the prepareResult(ResultSet) to transform a result set row to an object.

You can also do some stuff on the result set just after the query was executed using method afterExecuteQuery(ResultSet).

Since:

1.1.1

Author:

Tony Chemit - dev@tchemit.fr

Constructor Summary

Constructors

Constructor	Description
SqlQuery()

Method Summary

Modifier and Type	Method	Description
void	afterExecuteQuery(ResultSet set)	A hook to obtain the result set just after the query execute.
protected String[]	getColumnNames(ResultSet set)	Obtain the column names of a given result set using his metadata.
protected long	getNbRows(ResultSet set)	From a given result set, let's count his number of row.
protected Map<String,Object>	getRowAsMap(String[] columnNames, ResultSet set)	Given the column names of the result set, transform the row of the result set to a map with column name as key.
Optional<List<?>>	getSqlArgs()	This is optional : the instance may be capable to provide an args used for the SQL query.
Optional<String>	getSqlQuery()	This is optional : the instance may be capable to provide an SQL query.
abstract PreparedStatement	prepareQuery(Connection connection)	Prepare the statement used to do the sql query.
abstract O	prepareResult(ResultSet set)	given a result set, extract the data.
static <T> SqlQuery<T>	wrap(SqlFunction<Connection,PreparedStatement> preparer, SqlFunction<ResultSet,T> transformer)	Let's you easily create a SqlQuery using functional code-style.
static <T> SqlQuery<T>	wrap(String sqlQuery, SqlFunction<ResultSet,T> transformer)	Let's you easily create a SqlQuery using functional code-style.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SqlQuery

public SqlQuery()

Method Detail

prepareQuery

public abstract PreparedStatement prepareQuery(Connection connection)
                                        throws SQLException

Prepare the statement used to do the sql query.

Parameters:

connection - jdbc connection to use

Returns:

the statement containing the query to execute

Throws:

SQLException - if any problem

prepareResult

public abstract O prepareResult(ResultSet set)
                         throws SQLException

given a result set, extract the data.

Parameters:

set - the result set

Returns:

the data extracted from the current set, or null

Throws:

SQLException - if any prob

afterExecuteQuery

public void afterExecuteQuery(ResultSet set)
                       throws SQLException

A hook to obtain the result set just after the query execute.

Parameters:

set - the result set just obtained

Throws:

SQLException - if any prob

getColumnNames

protected String[] getColumnNames(ResultSet set)
                           throws SQLException

Obtain the column names of a given result set using his metadata.

Parameters:

set - the result set to inspect

Returns:

the column names of the result set

Throws:

SQLException - if any pb

getNbRows

protected long getNbRows(ResultSet set)
                  throws SQLException

From a given result set, let's count his number of row. Note: the result set must be scrollable to go back to before first row.

Parameters:

set - the result set to inspect

Returns:

the number of row of the given result set

Throws:

SQLException - if any pb

getRowAsMap

protected Map<String,Object> getRowAsMap(String[] columnNames,
                                               ResultSet set)
                                        throws SQLException

Given the column names of the result set, transform the row of the result set to a map with column name as key.

Parameters:

columnNames - column names of the result set

set - the set to inspect

Returns:

the map for the given row of the result set

Throws:

SQLException - if any pb

wrap

public static <T> SqlQuery<T> wrap(SqlFunction<Connection,PreparedStatement> preparer,
                                   SqlFunction<ResultSet,T> transformer)

Let's you easily create a SqlQuery using functional code-style.

Type Parameters:

T - the expected return type

Parameters:

preparer - used to create the PreparedStatement. See prepareQuery(Connection).

transformer - used to transform the ResultSet to the expected format. See prepareResult(ResultSet).

Returns:

a new SqlQuery instance using the given interfaces

See Also:

prepareQuery(Connection), prepareResult(ResultSet)

wrap

public static <T> SqlQuery<T> wrap(String sqlQuery,
                                   SqlFunction<ResultSet,T> transformer)

Let's you easily create a SqlQuery using functional code-style.

Type Parameters:

T - the expected return type

Parameters:

sqlQuery - an SQL query used to create the PreparedStatement. See prepareQuery(Connection).

transformer - used to transform the ResultSet to the expected format. See prepareResult(ResultSet).

Returns:

a new SqlQuery instance using the given interfaces

See Also:

prepareQuery(Connection), prepareResult(ResultSet)

getSqlQuery

public Optional<String> getSqlQuery()

This is optional : the instance may be capable to provide an SQL query. Otherwise this method will return an empty optional.

Returns:

the SQL query used or Optional.empty() if the SQL query is not available

getSqlArgs

public Optional<List<?>> getSqlArgs()

This is optional : the instance may be capable to provide an args used for the SQL query. Otherwise this method will return an empty optional.

Returns:

the args as map or Optional.empty() if the SQL args are not available