org.datanucleus.store.rdbms.sql

Class SQLStatementHelper

java.lang.Object

org.datanucleus.store.rdbms.sql.SQLStatementHelper

public class SQLStatementHelper
extends Object

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

Constructor Summary

Constructors

Constructor and Description
SQLStatementHelper()

Method Summary

Modifier and Type	Method and Description
static SQLTable	addJoinForOneToOneRelation(SQLStatement stmt, JavaTypeMapping sourceMapping, SQLTable sourceSqlTbl, JavaTypeMapping targetMapping, Table targetTable, String targetAlias, Object[] discrimValues, String targetTablegroupName, SQLJoin.JoinType joinType) Convenience method to add a join across a 1-1 relation to the provided SQLStatement.
static void	applyParametersToStatement(PreparedStatement ps, org.datanucleus.ExecutionContext ec, List<SQLStatementParameter> parameters, Map<Integer,String> paramNameByPosition, Map paramValuesByName) Convenience method to apply parameter values to the provided statement.
static List	getDiscriminatorValuesForMember(String className, JavaTypeMapping discMapping, RDBMSStoreManager storeMgr, org.datanucleus.ClassLoaderResolver clr) Method to return all possible discriminator values for the supplied class and its subclasses.
static BooleanExpression	getExpressionForDiscriminatorForClass(SQLStatement stmt, String className, org.datanucleus.metadata.DiscriminatorMetaData dismd, JavaTypeMapping discriminatorMapping, SQLTable discrimSqlTbl, org.datanucleus.ClassLoaderResolver clr) Convenience method to generate a BooleanExpression for the associated discriminator value for the specified class.
static SQLJoin.JoinType	getJoinTypeForOneToOneRelationJoin(JavaTypeMapping sourceMapping, SQLTable sourceSqlTbl, SQLJoin.JoinType joinType) Convenience method to return the join type to use for the specified 1-1 relation.
static PreparedStatement	getPreparedStatementForSQLStatement(SQLStatement sqlStmt, org.datanucleus.ExecutionContext ec, org.datanucleus.store.connection.ManagedConnection mconn, String resultSetType, String resultSetConcurrency) Convenience method to return a PreparedStatement for an SQLStatement.
static SQLTable	getSQLTableForMappingOfTable(SQLStatement stmt, SQLTable sqlTbl, JavaTypeMapping mapping) Method to return the SQLTable where the specified mapping (in the same table group as the provided SQLTable) is defined.
static Object	getValueForPrimaryKeyIndexOfObjectUsingReflection(Object value, int index, org.datanucleus.metadata.AbstractClassMetaData cmd, RDBMSStoreManager storeMgr, org.datanucleus.ClassLoaderResolver clr) Convenience method to use reflection to extract the value of a PK field of the provided object.
static void	selectFetchPlanOfCandidateInStatement(SQLStatement stmt, StatementClassMapping mappingDefinition, org.datanucleus.metadata.AbstractClassMetaData candidateCmd, org.datanucleus.FetchPlan fetchPlan, int maxFetchDepth) Method to select all fetch plan members for the candidate class.
static void	selectFetchPlanOfSourceClassInStatement(SQLStatement stmt, 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	selectFetchPlanOfSourceClassInStatement(SQLStatement stmt, StatementClassMapping mappingDefinition, org.datanucleus.FetchPlan fetchPlan, SQLTable sourceSqlTbl, org.datanucleus.metadata.AbstractClassMetaData sourceCmd, int maxFetchDepth, SQLJoin.JoinType inputJoinType) Method to select all fetch plan members for the "source" class.
static void	selectIdentityOfCandidateInStatement(SQLStatement stmt, StatementClassMapping mappingDefinition, org.datanucleus.metadata.AbstractClassMetaData candidateCmd) Method to select the identity for the candidate class.
static void	selectMemberOfSourceInStatement(SQLStatement stmt, StatementClassMapping mappingDefinition, org.datanucleus.FetchPlan fetchPlan, SQLTable sourceSqlTbl, org.datanucleus.metadata.AbstractMemberMetaData mmd, org.datanucleus.ClassLoaderResolver clr, int maxFetchPlanLimit, SQLJoin.JoinType inputJoinType) 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 PreparedStatement getPreparedStatementForSQLStatement(SQLStatement sqlStmt,
                                                                    org.datanucleus.ExecutionContext ec,
                                                                    org.datanucleus.store.connection.ManagedConnection mconn,
                                                                    String resultSetType,
                                                                    String resultSetConcurrency)
                                                             throws SQLException

Convenience method to return a PreparedStatement for an SQLStatement.

Parameters:

sqlStmt - The query expression

ec - execution context

mconn - The connection to use

resultSetType - Type of result set (if any)

resultSetConcurrency - result-set concurrency (if any)

Returns:

The PreparedStatement

Throws:

SQLException - If an error occurs in creation

applyParametersToStatement

public static void applyParametersToStatement(PreparedStatement ps,
                                              org.datanucleus.ExecutionContext ec,
                                              List<SQLStatementParameter> parameters,
                                              Map<Integer,String> paramNameByPosition,
                                              Map paramValuesByName)

Convenience method to apply parameter values to the provided statement.

Parameters:

ps - The prepared statement

ec - ExecutionContext

parameters - The parameters

paramNameByPosition - Optional map of parameter names keyed by the position

paramValuesByName - Value of parameter keyed by name (or position)

getValueForPrimaryKeyIndexOfObjectUsingReflection

public static Object getValueForPrimaryKeyIndexOfObjectUsingReflection(Object value,
                                                                       int index,
                                                                       org.datanucleus.metadata.AbstractClassMetaData cmd,
                                                                       RDBMSStoreManager storeMgr,
                                                                       org.datanucleus.ClassLoaderResolver clr)

Convenience method to use reflection to extract the value of a PK field of the provided object.

Parameters:

value - The value of the overall object

index - Index of the PK field whose value we need to return

cmd - Metadata for the class

storeMgr - Store manager

clr - ClassLoader resolver

Returns:

Value of this index of the PK field

getSQLTableForMappingOfTable

public static SQLTable getSQLTableForMappingOfTable(SQLStatement stmt,
                                                    SQLTable sqlTbl,
                                                    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)

selectIdentityOfCandidateInStatement

public static void selectIdentityOfCandidateInStatement(SQLStatement stmt,
                                                        StatementClassMapping mappingDefinition,
                                                        org.datanucleus.metadata.AbstractClassMetaData candidateCmd)

Method to select the identity for the candidate class. The supplied statement and mapping definition are updated during this method. Selects the datastore id (if using datastore id) as "DN_DATASTOREID", the version (if present) as "DN_VERSION", the discriminator (if present) as "DN_DISCRIM", and the application id (if using application id) as "DN_APPID_{i}"

Parameters:

stmt - The statement

mappingDefinition - Mapping definition for result columns

candidateCmd - The candidate class meta-data

selectFetchPlanOfCandidateInStatement

public static void selectFetchPlanOfCandidateInStatement(SQLStatement stmt,
                                                         StatementClassMapping mappingDefinition,
                                                         org.datanucleus.metadata.AbstractClassMetaData candidateCmd,
                                                         org.datanucleus.FetchPlan fetchPlan,
                                                         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

candidateCmd - The candidate class meta-data

fetchPlan - FetchPlan in use

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

selectFetchPlanOfSourceClassInStatement

public static void selectFetchPlanOfSourceClassInStatement(SQLStatement stmt,
                                                           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)

selectFetchPlanOfSourceClassInStatement

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

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)

inputJoinType - Optional join type to use for subobjects (otherwise decide join type internally)

selectMemberOfSourceInStatement

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

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)

inputJoinType - Optional join type to use for subobjects (otherwise decide join type internally)

addJoinForOneToOneRelation

public static SQLTable addJoinForOneToOneRelation(SQLStatement stmt,
                                                  JavaTypeMapping sourceMapping,
                                                  SQLTable sourceSqlTbl,
                                                  JavaTypeMapping targetMapping,
                                                  Table targetTable,
                                                  String targetAlias,
                                                  Object[] discrimValues,
                                                  String targetTablegroupName,
                                                  SQLJoin.JoinType joinType)

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 join type isn't provided and 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. If the join type is supplied then it is respected.

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)

joinType - Type of join to use (if known). If not known will use based on whether nullable

Returns:

The SQLTable for the target once the join is added

getJoinTypeForOneToOneRelationJoin

public static SQLJoin.JoinType getJoinTypeForOneToOneRelationJoin(JavaTypeMapping sourceMapping,
                                                                  SQLTable sourceSqlTbl,
                                                                  SQLJoin.JoinType joinType)

Convenience method to return the join type to use for the specified 1-1 relation. If the join type isn't provided and 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:

sourceMapping - Mapping of the relation in the source table

sourceSqlTbl - Source table in the SQLStatement

joinType - Join type to use if already known; will be returned if not null

Returns:

Join type that should be used for this 1-1 relation

getExpressionForDiscriminatorForClass

public static BooleanExpression getExpressionForDiscriminatorForClass(SQLStatement stmt,
                                                                      String className,
                                                                      org.datanucleus.metadata.DiscriminatorMetaData dismd,
                                                                      JavaTypeMapping discriminatorMapping,
                                                                      SQLTable discrimSqlTbl,
                                                                      org.datanucleus.ClassLoaderResolver clr)

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

clr - ClassLoader resolver

Returns:

Boolean expression for this discriminator value

getDiscriminatorValuesForMember

public static List getDiscriminatorValuesForMember(String className,
                                                   JavaTypeMapping discMapping,
                                                   RDBMSStoreManager 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