net.as_development.asdk.db_service

Interface ISqlGenerator

All Known Implementing Classes:

AnsiSqlGenerator

public interface ISqlGenerator

Implementations of those interface must be used to generate any kind of SQL statements. But different implementations can generate different statements for different DB products. Thats because ANSI SQL isn't support 100% by an DB product ...

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ISqlGenerator.ESqlError
static class	ISqlGenerator.EStatementType

Method Summary

Modifier and Type	Method and Description
String	createSql(ISqlGenerator.EStatementType eStatement, Row aMeta, IDBBackendQuery iQuery) create a new SQL statement for the given set of parameters.
Object	getValueFromResultSet(ResultSet aResult, String sColumn, Class<?> aType) extract an entity member value from the given result set.
String	mapJavaTypeToSqlType(Column aMeta) map the given Java type of an entity member to the corresponding SQL type to be used within SQL statements.
ISqlGenerator.ESqlError	mapSqlExceptionToError(SQLException aException) map the given SQL exception to an suitable error code.
void	setValueOnPreparedStatement(PreparedStatement aSql, int nIndex, Class<?> aType, Object aValue) set the given value on the also given PreparedStatement.

Method Detail

mapSqlExceptionToError

ISqlGenerator.ESqlError mapSqlExceptionToError(SQLException aException)
                                        throws Exception

map the given SQL exception to an suitable error code. Because such states depend from the real DB used here ... and ISqlGenerator implementation represent such 'real DB' ... it's up to this code to map those error states/codes.

Parameters:

aException - [IN] the SQL exception to be 'translated' here.

Returns:

the corresponding internal error code.

Throws:

Exception

createSql

String createSql(ISqlGenerator.EStatementType eStatement,
                 Row aMeta,
                 IDBBackendQuery iQuery)
          throws Exception

create a new SQL statement for the given set of parameters. Those statement must contain place holder instead of real values. Because it's used later in combination with a PreparedStatement instance.

Parameters:

eStatement - [IN] describe the requested SQL statement.

aMeta - [IN] all meta data describing the entity more in detail.

iQuery - [IN, OPTIONAL] describe a SQL query more in detail. Can be null if no query is requested.

Returns:

the generated SQL statement containing place holder.

Throws:

Exception

mapJavaTypeToSqlType

String mapJavaTypeToSqlType(Column aMeta)
                     throws Exception

map the given Java type of an entity member to the corresponding SQL type to be used within SQL statements.

Parameters:

aMeta - [IN] describe the entity member type.

Returns:

the corresponding SQL type.

Throws:

Exception

setValueOnPreparedStatement

void setValueOnPreparedStatement(PreparedStatement aSql,
                                 int nIndex,
                                 Class<?> aType,
                                 Object aValue)
                          throws Exception

set the given value on the also given PreparedStatement.

Parameters:

aSql - [IN, OUT] the prepared statement where the value must be set.

nIndex - [IN] the position of the place holder which must be replaced within the prepared statement.

aType - [IN] the java type of the given value.

aValue - [IN] the value to be set on the prepared statement.

Throws:

Exception

getValueFromResultSet

Object getValueFromResultSet(ResultSet aResult,
                             String sColumn,
                             Class<?> aType)
                      throws Exception

extract an entity member value from the given result set.

Parameters:

aResult - [IN] the result set where the value must be read from.

sColumn - [IN] the column where the value must be read from.

aType - [IN] the java type of this value so it's casted right.

Returns:

the value.

Throws:

Exception