org.datanucleus.store.rdbms.sql
Class SQLStatementHelper

java.lang.Object
  org.datanucleus.store.rdbms.sql.SQLStatementHelper

public class SQLStatementHelper
extends java.lang.Object

Series of convenience methods to help the process of generating SQLStatements.

Constructor Summary

SQLStatementHelper()

Method Summary

static SQLTable	addJoinForOneToOneRelation(SQLStatement stmt, org.datanucleus.store.mapped.mapping.JavaTypeMapping sourceMapping, SQLTable sourceSqlTbl, org.datanucleus.store.mapped.mapping.JavaTypeMapping targetMapping, org.datanucleus.store.mapped.DatastoreContainerObject targetTable, java.lang.String targetAlias, java.lang.Object[] discrimValues, java.lang.String targetTablegroupName) Convenience method to add a join across a 1-1 relation to the provided SQLStatement.
static java.util.List	getDiscriminatorValuesForMember(java.lang.String className, org.datanucleus.store.mapped.mapping.JavaTypeMapping discMapping, RDBMSManager storeMgr, org.datanucleus.ClassLoaderResolver clr) Method to return all possible discriminator values for the supplied class and its subclasses.
static BooleanExpression	getExpressionForDiscriminatorForClass(SQLStatement stmt, java.lang.String className, org.datanucleus.metadata.DiscriminatorMetaData dismd, org.datanucleus.store.mapped.mapping.JavaTypeMapping discriminatorMapping, SQLTable discrimSqlTbl) Convenience method to generate a BooleanExpression for the associated discriminator value for the specified class.
static java.sql.PreparedStatement	getPreparedStatementForSQLStatement(SQLStatement sqlStmt, org.datanucleus.ObjectManager om, org.datanucleus.ManagedConnection mconn, java.lang.String resultSetType, java.lang.String resultSetConcurrency) Convenience method to return a PreparedStatement for an SQLStatement.
static SQLTable	getSQLTableForMappingOfTable(SQLStatement stmt, SQLTable sqlTbl, org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping) Method to return the SQLTable where the specified mapping (in the same table group as the provided SQLTable) is defined.
static void	selectFetchPlanOfCandidateInStatement(SQLStatement stmt, org.datanucleus.store.mapped.StatementClassMapping mappingDefinition, org.datanucleus.FetchPlan fetchPlan, org.datanucleus.metadata.AbstractClassMetaData candidateCmd, int maxFetchDepth) Method to select all fetch plan members for the candidate class.
static void	selectFetchPlanOfSourceClassInStatement(SQLStatement stmt, org.datanucleus.store.mapped.StatementClassMapping mappingDefinition, org.datanucleus.FetchPlan fetchPlan, SQLTable sourceSqlTbl, org.datanucleus.metadata.AbstractClassMetaData sourceCmd, int maxFetchDepth) Method to select all fetch plan members for the "source" class.
static void	selectMemberOfSourceInStatement(SQLStatement stmt, org.datanucleus.store.mapped.StatementClassMapping mappingDefinition, org.datanucleus.FetchPlan fetchPlan, SQLTable sourceSqlTbl, org.datanucleus.metadata.AbstractMemberMetaData mmd, org.datanucleus.ClassLoaderResolver clr, int maxFetchPlanLimit) Method to select the specified member (field/property) of the source table in the passed SQL statement.

Methods inherited from class java.lang.Object

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

Constructor Detail

SQLStatementHelper

public SQLStatementHelper()

Method Detail

getPreparedStatementForSQLStatement

public static java.sql.PreparedStatement getPreparedStatementForSQLStatement(SQLStatement sqlStmt,
                                                                             org.datanucleus.ObjectManager om,
                                                                             org.datanucleus.ManagedConnection mconn,
                                                                             java.lang.String resultSetType,
                                                                             java.lang.String resultSetConcurrency)
                                                                      throws java.sql.SQLException

Convenience method to return a PreparedStatement for an SQLStatement.

Parameters:

sqlStmt - The query expression

om - ObjectManager

mconn - The connection to use

resultSetType - Type of result set (if any)

resultSetConcurrency - result-set concurrency (if any)

Returns:

The PreparedStatement

Throws:

java.sql.SQLException - If an error occurs in creation

getSQLTableForMappingOfTable

public static SQLTable getSQLTableForMappingOfTable(SQLStatement stmt,
                                                    SQLTable sqlTbl,
                                                    org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)

Method to return the SQLTable where the specified mapping (in the same table group as the provided SQLTable) is defined. If the statement doesn't currently join to the required table then a join will be added. If the required table is a superclass table then the join will be INNER. If the required table is a secondary table then the join will be defined by the meta-data for the secondary table. If this table group is NOT the candidate table group then LEFT OUTER JOIN will be used.

Parameters:

stmt - The statement

sqlTbl - SQLTable to start from for the supplied mapping (may be in super-table, or secondary-table of this)

mapping - The mapping

Returns:

The SQLTable for this mapping (may have been added to the statement during this method)

selectFetchPlanOfCandidateInStatement

public static void selectFetchPlanOfCandidateInStatement(SQLStatement stmt,
                                                         org.datanucleus.store.mapped.StatementClassMapping mappingDefinition,
                                                         org.datanucleus.FetchPlan fetchPlan,
                                                         org.datanucleus.metadata.AbstractClassMetaData candidateCmd,
                                                         int maxFetchDepth)

Method to select all fetch plan members for the candidate class. The supplied statement and mapping definition are updated during this method. Shortcut to calling "selectFetchPlanOfSourceClassInStatement".

Parameters:

stmt - The statement

mappingDefinition - Mapping definition for result columns

fetchPlan - FetchPlan in use

candidateCmd - The candidate class meta-data

maxFetchDepth - Max fetch depth from this point to select (0 implies no other objects)

selectFetchPlanOfSourceClassInStatement

public static void selectFetchPlanOfSourceClassInStatement(SQLStatement stmt,
                                                           org.datanucleus.store.mapped.StatementClassMapping mappingDefinition,
                                                           org.datanucleus.FetchPlan fetchPlan,
                                                           SQLTable sourceSqlTbl,
                                                           org.datanucleus.metadata.AbstractClassMetaData sourceCmd,
                                                           int maxFetchDepth)

Method to select all fetch plan members for the "source" class. If the passed FetchPlan is null then the default fetch group fields will be selected. The source class is defined by the supplied meta-data, and the SQLTable that we are selecting from. The supplied statement and mapping definition are updated during this method.

Parameters:

stmt - The statement

mappingDefinition - Mapping definition for result columns (populated with column positions of any selected mappings if provided as input)

fetchPlan - FetchPlan in use

sourceSqlTbl - SQLTable for the source class that we select from

sourceCmd - Meta-data for the source class

maxFetchDepth - Max fetch depth from this point to select (0 implies no other objects)

selectMemberOfSourceInStatement

public static void selectMemberOfSourceInStatement(SQLStatement stmt,
                                                   org.datanucleus.store.mapped.StatementClassMapping mappingDefinition,
                                                   org.datanucleus.FetchPlan fetchPlan,
                                                   SQLTable sourceSqlTbl,
                                                   org.datanucleus.metadata.AbstractMemberMetaData mmd,
                                                   org.datanucleus.ClassLoaderResolver clr,
                                                   int maxFetchPlanLimit)

Method to select the specified member (field/property) of the source table in the passed SQL statement. This populates the mappingDefinition with the column details for this member.

Parameters:

stmt - The SQL statement

mappingDefinition - Mapping definition for the results (will be populated by any selected mappings if provided as input)

fetchPlan - FetchPlan

sourceSqlTbl - Table that has the member (or a super-table/secondary-table of this table)

mmd - Meta-data for the field/property in the source that we are selecting

clr - ClassLoader resolver

maxFetchPlanLimit - Max fetch depth from this point to select (0 implies no other objects)

addJoinForOneToOneRelation

public static SQLTable addJoinForOneToOneRelation(SQLStatement stmt,
                                                  org.datanucleus.store.mapped.mapping.JavaTypeMapping sourceMapping,
                                                  SQLTable sourceSqlTbl,
                                                  org.datanucleus.store.mapped.mapping.JavaTypeMapping targetMapping,
                                                  org.datanucleus.store.mapped.DatastoreContainerObject targetTable,
                                                  java.lang.String targetAlias,
                                                  java.lang.Object[] discrimValues,
                                                  java.lang.String targetTablegroupName)

Convenience method to add a join across a 1-1 relation to the provided SQLStatement. Returns the SQLTable for the other side of the relation. If the ID is in the target and FK in the source and the FK is not nullable then an "inner join" is used, otherwise a "left outer join" is used to cater for null values.

Parameters:

stmt - The SQLStatement

sourceMapping - Mapping of the relation in the source table

sourceSqlTbl - Source table in the SQLStatement

targetMapping - Mapping of the relation in the target table

targetTable - Target table in the datastore

targetAlias - Alias for target table to use in SQLStatement

discrimValues - Any discriminator values to apply to restrict the target side (if any)

targetTablegroupName - Name of the tablegroup that the target SQLTable should be in (if known)

Returns:

The SQLTable for the target once the join is added

getExpressionForDiscriminatorForClass

public static BooleanExpression getExpressionForDiscriminatorForClass(SQLStatement stmt,
                                                                      java.lang.String className,
                                                                      org.datanucleus.metadata.DiscriminatorMetaData dismd,
                                                                      org.datanucleus.store.mapped.mapping.JavaTypeMapping discriminatorMapping,
                                                                      SQLTable discrimSqlTbl)

Convenience method to generate a BooleanExpression for the associated discriminator value for the specified class.

Parameters:

stmt - The Query Statement to be updated

className - The class name

dismd - MetaData for the discriminator

discriminatorMapping - Mapping for the discriminator

discrimSqlTbl - SQLTable for the table with the discriminator

Returns:

Boolean expression for this discriminator value

getDiscriminatorValuesForMember

public static java.util.List getDiscriminatorValuesForMember(java.lang.String className,
                                                             org.datanucleus.store.mapped.mapping.JavaTypeMapping discMapping,
                                                             RDBMSManager storeMgr,
                                                             org.datanucleus.ClassLoaderResolver clr)

Method to return all possible discriminator values for the supplied class and its subclasses.

Parameters:

className - Name of the class

discMapping - The discriminator mapping

storeMgr - StoreManager

clr - ClassLoader resolver

Returns:

The possible discriminator values