org.springframework.jdbc.object: public class: SqlFunction

org.springframework.jdbc.object
public class: SqlFunction [javadoc | source]

java.lang.Object
   org.springframework.jdbc.object.RdbmsOperation
      org.springframework.jdbc.object.SqlOperation
         org.springframework.jdbc.object.SqlQuery
            org.springframework.jdbc.object.MappingSqlQueryWithParameters
               org.springframework.jdbc.object.MappingSqlQuery
                  org.springframework.jdbc.object.SqlFunction

All Implemented Interfaces:
InitializingBean

SQL "function" wrapper for a query that returns a single row of results. The default behavior is to return an int, but that can be overridden by using the constructor with an extra return type parameter.

Intended to use to call SQL functions that return a single result using a query like "select user()" or "select sysdate from dual". It is not intended for calling more complex stored functions or for using a CallableStatement to invoke a stored procedure or stored function. Use StoredProcedure or SqlCall for this type of processing.

This is a concrete class, which there is often no need to subclass. Code using this package can create an object of this type, declaring SQL and parameters, and then invoke the appropriate run method repeatedly to execute the function. Subclasses are only supposed to add specialized run methods for specific parameter and return types.

Like all RdbmsOperation objects, SqlFunction objects are thread-safe.

Also see:

org.springframework.jdbc.object.StoredProcedure

author: Rod - Johnson

author: Juergen - Hoeller

author: Jean-Pierre - Pawlak

Fields inherited from org.springframework.jdbc.object.RdbmsOperation:
logger

Constructor:

Constructor:
public SqlFunction() { setRowsExpected(1); } Constructor to allow use as a JavaBean. A DataSource, SQL and any parameters must be supplied before invoking the `compile` method and using this object. Also see: setDataSource setSql compile
public SqlFunction(DataSource ds, String sql) { setRowsExpected(1); setDataSource(ds); setSql(sql); } Create a new SqlFunction object with SQL, but without parameters. Must add parameters or settle with none. Parameters: `ds` - DataSource to obtain connections from `sql` - SQL to execute
public SqlFunction(DataSource ds, String sql, int[] types) { setRowsExpected(1); setDataSource(ds); setSql(sql); setTypes(types); } Create a new SqlFunction object with SQL and parameters. Parameters: `ds` - DataSource to obtain connections from `sql` - SQL to execute `types` - SQL types of the parameters, as defined in the `java.sql.Types` class Also see: java.sql.Types
public SqlFunction(DataSource ds, String sql, int[] types, Class resultType) { setRowsExpected(1); setDataSource(ds); setSql(sql); setTypes(types); setResultType(resultType); } Create a new SqlFunction object with SQL, parameters and a result type. Parameters: `ds` - DataSource to obtain connections from `sql` - SQL to execute `types` - SQL types of the parameters, as defined in the `java.sql.Types` class `resultType` - the type that the result object is required to match Also see: setResultType(Class) java.sql.Types

 public SqlFunction() {
	                               	 
		setRowsExpected(1);
}

Constructor to allow use as a JavaBean. A DataSource, SQL and any parameters must be supplied before invoking the compile method and using this object.

Also see:

setDataSource

setSql

compile

 public SqlFunction(DataSource ds,
    String sql) {
		setRowsExpected(1);
		setDataSource(ds);
		setSql(sql);
}

Create a new SqlFunction object with SQL, but without parameters. Must add parameters or settle with none.

Parameters:

ds - DataSource to obtain connections from

sql - SQL to execute

 public SqlFunction(DataSource ds,
    String sql,
    int[] types) {
		setRowsExpected(1);
		setDataSource(ds);
		setSql(sql);
		setTypes(types);
}

Create a new SqlFunction object with SQL and parameters.

Parameters:

ds - DataSource to obtain connections from

sql - SQL to execute

types - SQL types of the parameters, as defined in the java.sql.Types class

Also see:

java.sql.Types

 public SqlFunction(DataSource ds,
    String sql,
    int[] types,
    Class resultType) {
		setRowsExpected(1);
		setDataSource(ds);
		setSql(sql);
		setTypes(types);
		setResultType(resultType);
}

Create a new SqlFunction object with SQL, parameters and a result type.

Parameters:

ds - DataSource to obtain connections from

sql - SQL to execute

types - SQL types of the parameters, as defined in the java.sql.Types class

resultType - the type that the result object is required to match

Also see:

setResultType(Class)

java.sql.Types

Method from org.springframework.jdbc.object.SqlFunction Summary:
mapRow, run, run, run, runGeneric, runGeneric, runGeneric, setResultType

Methods from org.springframework.jdbc.object.MappingSqlQuery:
mapRow, mapRow

Methods from org.springframework.jdbc.object.MappingSqlQueryWithParameters:
mapRow, newRowMapper

Methods from org.springframework.jdbc.object.SqlQuery:
execute, execute, execute, execute, execute, execute, execute, execute, execute, execute, execute, execute, executeByNamedParam, executeByNamedParam, findObject, findObject, findObject, findObject, findObject, findObject, findObject, findObject, findObject, findObject, findObjectByNamedParam, findObjectByNamedParam, getRowsExpected, newRowMapper, setRowsExpected

Methods from org.springframework.jdbc.object.SqlOperation:
compileInternal, getParsedSql, newPreparedStatementCreator, newPreparedStatementCreator, newPreparedStatementSetter, onCompileInternal

Methods from org.springframework.jdbc.object.RdbmsOperation:
afterPropertiesSet, allowsUnusedParameters, checkCompiled, compile, compileInternal, declareParameter, getDeclaredParameters, getGeneratedKeysColumnNames, getJdbcTemplate, getResultSetType, getSql, isCompiled, isReturnGeneratedKeys, isUpdatableResults, setDataSource, setFetchSize, setGeneratedKeysColumnNames, setJdbcTemplate, setMaxRows, setParameters, setQueryTimeout, setResultSetType, setReturnGeneratedKeys, setSql, setTypes, setUpdatableResults, supportsLobParameters, validateNamedParameters, validateParameters

Methods from org.springframework.jdbc.object.RdbmsOperation:

afterPropertiesSet, allowsUnusedParameters, checkCompiled, compile, compileInternal, declareParameter, getDeclaredParameters, getGeneratedKeysColumnNames, getJdbcTemplate, getResultSetType, getSql, isCompiled, isReturnGeneratedKeys, isUpdatableResults, setDataSource, setFetchSize, setGeneratedKeysColumnNames, setJdbcTemplate, setMaxRows, setParameters, setQueryTimeout, setResultSetType, setReturnGeneratedKeys, setSql, setTypes, setUpdatableResults, supportsLobParameters, validateNamedParameters, validateParameters

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.springframework.jdbc.object.SqlFunction Detail:
protected Object mapRow(ResultSet rs, int rowNum) throws SQLException { return this.rowMapper.mapRow(rs, rowNum); } This implementation of this method extracts a single value from the single row returned by the function. If there are a different number of rows returned, this is treated as an error.
public int run() { return run(null); } Convenient method to run the function without arguments.
public int run(int parameter) { return run(new Object[] {new Integer(parameter)}); } Convenient method to run the function with a single int argument.
public int run(Object[] parameters) { Object obj = super.findObject(parameters); if (!(obj instanceof Number)) { throw new TypeMismatchDataAccessException("Couldn't convert result object [" + obj + "] to int"); } return ((Number) obj).intValue(); } Analogous to the SqlQuery.execute([]) method. This is a generic method to execute a query, taken a number of arguments.
public Object runGeneric() { return findObject((Object[]) null); } Convenient method to run the function without arguments, returning the value as an object.
public Object runGeneric(int parameter) { return findObject(parameter); } Convenient method to run the function with a single int argument.
public Object runGeneric(Object[] parameters) { return findObject(parameters); } Analogous to the `SqlQuery.findObject(Object[])` method. This is a generic method to execute a query, taken a number of arguments.
public void setResultType(Class resultType) { this.rowMapper.setRequiredType(resultType); } Specify the type that the result object is required to match. If not specified, the result value will be exposed as returned by the JDBC driver.

Method from org.springframework.jdbc.object.SqlFunction Detail:

 protected Object mapRow(ResultSet rs,
    int rowNum) throws SQLException {
		return this.rowMapper.mapRow(rs, rowNum);
}

This implementation of this method extracts a single value from the single row returned by the function. If there are a different number of rows returned, this is treated as an error.

 public int run() {
		return run(null);
}

Convenient method to run the function without arguments.

 public int run(int parameter) {
		return run(new Object[] {new Integer(parameter)});
}

Convenient method to run the function with a single int argument.

 public int run(Object[] parameters) {
		Object obj = super.findObject(parameters);
		if (!(obj instanceof Number)) {
			throw new TypeMismatchDataAccessException("Couldn't convert result object [" + obj + "] to int");
		}
		return ((Number) obj).intValue();
}

Analogous to the SqlQuery.execute([]) method. This is a generic method to execute a query, taken a number of arguments.

 public Object runGeneric() {
		return findObject((Object[]) null);
}

Convenient method to run the function without arguments, returning the value as an object.

 public Object runGeneric(int parameter) {
		return findObject(parameter);
}

Convenient method to run the function with a single int argument.

 public Object runGeneric(Object[] parameters) {
		return findObject(parameters);
}

SqlQuery.findObject(Object[])

 public  void setResultType(Class resultType) {
		this.rowMapper.setRequiredType(resultType);
}

If not specified, the result value will be exposed as returned by the JDBC driver.