org.datanucleus.store.rdbms.query
Class QueryToSQLMapper

java.lang.Object
  org.datanucleus.query.evaluator.AbstractExpressionEvaluator
      org.datanucleus.store.rdbms.query.QueryToSQLMapper

All Implemented Interfaces:

org.datanucleus.query.expression.ExpressionEvaluator, QueryGenerator

public class QueryToSQLMapper
extends org.datanucleus.query.evaluator.AbstractExpressionEvaluator
implements QueryGenerator

Class which maps a compiled (generic) query to an SQL query for RDBMS datastores. Takes in an SQLStatement, and use of compile() will update the SQLStatement to reflect the filter, result, grouping, having, ordering etc.

Supports the following extensions currently :-

• datanucleus.query.jdoql.{varName}.join defines the join type for that alias. This only currently applies if the variable is (finally) bound using the equality operator (e.g var.field == this.field). The extension should be set to "LEFTOUTERJOIN", "INNERJOIN"

Field Summary

protected static org.datanucleus.util.Localiser	LOCALISER Localiser for messages.
protected static org.datanucleus.util.Localiser	LOCALISER_RDBMS Localiser for messages.
static String	OPTION_BULK_UPDATE_VERSION
static String	OPTION_CASE_INSENSITIVE
static String	OPTION_EXPLICIT_JOINS
QueryToSQLMapper	parentMapper Parent mapper if we are processing a subquery.

Constructor Summary

QueryToSQLMapper(SQLStatement stmt, org.datanucleus.query.compiler.QueryCompilation compilation, Map parameters, org.datanucleus.store.mapped.StatementClassMapping resultDefForClass, StatementResultMapping resultDef, org.datanucleus.metadata.AbstractClassMetaData cmd, org.datanucleus.FetchPlan fetchPlan, org.datanucleus.store.ExecutionContext ec, org.datanucleus.util.Imports importsDefinition, Set<String> options, Map<String,Object> extensions)
Constructor.

Method Summary

void	bindParameter(String paramName, Class type) Method to bind the specified parameter to the defined type.
void	bindVariable(String varName, org.datanucleus.metadata.AbstractClassMetaData cmd, SQLTable sqlTbl, org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping) Method to bind the specified variable to the table and mapping.
SQLExpression	bindVariable(UnboundExpression expr, Class type) Method to bind the specified unbound variable (as cross join) on the assumption that the type is a persistable class.
void	compile() Method to update the supplied SQLStatement with the components of the specified query.
protected void	compileFilter() Method to compile the WHERE clause of the query into the SQLStatement.
protected void	compileFrom() Method to compile the FROM clause of the query into the SQLStatement.
protected void	compileFromClassExpression(org.datanucleus.query.expression.ClassExpression clsExpr) Method to take a ClassExpression (in a FROM clause) and process the candidate and any linked JoinExpression(s), adding joins to the SQLStatement as required.
protected void	compileGrouping() Method to compile the grouping clause of the query into the SQLStatement.
protected void	compileHaving() Method to compile the having clause of the query into the SQLStatement.
protected void	compileOrdering() Method to compile the ordering clause of the query into the SQLStatement.
protected void	compileResult() Method to compile the result clause of the query into the SQLStatement.
String	getAliasForSQLTable(SQLTable tbl) Returns the alias used for the specified SQLTable.
protected BooleanExpression	getBooleanExpressionForUseInFilter(BooleanExpression expr) Convenience method to return a boolean expression suitable for using in a filter.
org.datanucleus.ClassLoaderResolver	getClassLoaderResolver() Accessor for the ClassLoader resolver to use when looking up classes.
org.datanucleus.query.compiler.CompilationComponent	getCompilationComponent() Accessor for the current query component being compiled.
org.datanucleus.store.ExecutionContext	getExecutionContext() Accessor for the ExecutionContext for this query.
Map<Integer,String>	getParameterNameByPosition() Convenience accessor for a map of the parameter name keyed by its position.
Object	getProperty(String name) Accessor for a property affecting the query compilation.
String	getQueryLanguage() Accessor for the query language that this query pertains to.
SQLJoin.JoinType	getRequiredJoinTypeForAlias(String alias) Convenience method to return the required join type for the specified alias.
SQLTable	getSQLTableForAlias(String alias) Method to return the SQLTable for the specified primary expression "alias".
protected org.datanucleus.store.rdbms.query.QueryToSQLMapper.SQLTableMapping	getSQLTableMappingForAlias(String alias)
protected StatementNewObjectMapping	getStatementMappingForNewObjectExpression(NewObjectExpression expr) Convenience method to convert a NewObjectExpression into a StatementNewObjectMapping.
Class	getTypeOfVariable(String varName) Accessor for the type of a variable if already known (declared?).
Object	getValueForExtension(String key) Accessor for the value of the specified query extension (or null if not defined).
protected Object	getValueForObjectField(Object obj, String fieldName) Convenience method to return the value of a field of the supplied object.
boolean	hasExplicitJoins() Accessor for whether the query has explicit variables.
boolean	hasExtension(String key) Accessor for whether the query being generated has the specified extension.
protected boolean	hasSQLTableMappingForAlias(String alias)
boolean	isPrecompilable() Accessor for whether the query is precompilable (doesn't need to know parameter values to be able to compile it).
protected Object	processAddExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processAndExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processCaseExpression(org.datanucleus.query.expression.CaseExpression expr)
protected Object	processCastExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processComExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processCreatorExpression(org.datanucleus.query.expression.CreatorExpression expr)
protected Object	processDistinctExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processDivExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processEqExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processGteqExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processGtExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processInExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processInvokeExpression(org.datanucleus.query.expression.InvokeExpression expr)
protected Object	processIsExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processIsnotExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processLikeExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processLiteral(org.datanucleus.query.expression.Literal expr)
protected Object	processLteqExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processLtExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processModExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processMulExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processNegExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processNoteqExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processNotExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processNotInExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processOrExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processParameterExpression(org.datanucleus.query.expression.ParameterExpression expr)
protected Object	processParameterExpression(org.datanucleus.query.expression.ParameterExpression expr, boolean asLiteral) Method to process a parameter expression.
protected Object	processPrimaryExpression(org.datanucleus.query.expression.PrimaryExpression expr)
protected Object	processSubExpression(org.datanucleus.query.expression.Expression expr)
protected Object	processSubqueryExpression(org.datanucleus.query.expression.SubqueryExpression expr)
protected SQLExpression	processUnboundExpression(UnboundExpression expr)
protected Object	processVariableExpression(org.datanucleus.query.expression.VariableExpression expr)
protected SQLExpression	replaceParameterLiteral(ParameterLiteral paramLit, org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping) Convenience method to return a parameter-based literal using the supplied mapping to replace the provided ParameterLiteral (generated before its type was known).
Class	resolveClass(String className) Convenience method to resolve a class name.
protected void	setNotPrecompilable()
protected void	setSQLTableMappingForAlias(String alias, org.datanucleus.store.rdbms.query.QueryToSQLMapper.SQLTableMapping mapping)
void	useParameterExpressionAsLiteral(SQLLiteral paramLiteral) Method to instruct the generator to convert the provided parameter expression to just be a literal using the value of the parameter (hence the statement cannot be precompilable since the value needs to be known).
protected void	validateExpressionForResult(SQLExpression sqlExpr) Method that validates that the specified expression is valid for use in a result clause.

Methods inherited from class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

compileAdditiveMultiplicativeExpression, compileOrAndExpression, compilePrimaryExpression, compileRelationalExpression, compileUnaryExpression, evaluate

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER

protected static final org.datanucleus.util.Localiser LOCALISER

Localiser for messages.

LOCALISER_RDBMS

protected static final org.datanucleus.util.Localiser LOCALISER_RDBMS

Localiser for messages.

OPTION_CASE_INSENSITIVE

public static final String OPTION_CASE_INSENSITIVE

See Also:

Constant Field Values

OPTION_EXPLICIT_JOINS

public static final String OPTION_EXPLICIT_JOINS

See Also:

Constant Field Values

OPTION_BULK_UPDATE_VERSION

public static final String OPTION_BULK_UPDATE_VERSION

See Also:

Constant Field Values

parentMapper

public QueryToSQLMapper parentMapper

Parent mapper if we are processing a subquery.

Constructor Detail

QueryToSQLMapper

public QueryToSQLMapper(SQLStatement stmt,
                        org.datanucleus.query.compiler.QueryCompilation compilation,
                        Map parameters,
                        org.datanucleus.store.mapped.StatementClassMapping resultDefForClass,
                        StatementResultMapping resultDef,
                        org.datanucleus.metadata.AbstractClassMetaData cmd,
                        org.datanucleus.FetchPlan fetchPlan,
                        org.datanucleus.store.ExecutionContext ec,
                        org.datanucleus.util.Imports importsDefinition,
                        Set<String> options,
                        Map<String,Object> extensions)

Constructor.

Parameters:

stmt - SQL Statement to update with the query contents.

compilation - The generic query compilation

parameters - Parameters needed

resultDefForClass - Definition of results for the statement (populated here)

resultDef - Definition of results if we have a result clause (populated here)

cmd - Metadata for the candidate class

fetchPlan - Fetch Plan to apply

ec - execution context

importsDefinition - Import definition to use in class lookups (optional)

options - Options controlling behaviour

extensions - Any query extensions that may define compilation behaviour

Method Detail

getQueryLanguage

public String getQueryLanguage()

Accessor for the query language that this query pertains to. Can be used to decide how to handle the input.

Specified by:

getQueryLanguage in interface QueryGenerator

Returns:

The query language

getClassLoaderResolver

public org.datanucleus.ClassLoaderResolver getClassLoaderResolver()

Description copied from interface: QueryGenerator

Accessor for the ClassLoader resolver to use when looking up classes.

Specified by:

getClassLoaderResolver in interface QueryGenerator

Returns:

The classloader resolver

getCompilationComponent

public org.datanucleus.query.compiler.CompilationComponent getCompilationComponent()

Description copied from interface: QueryGenerator

Accessor for the current query component being compiled.

Specified by:

getCompilationComponent in interface QueryGenerator

Returns:

Component being compiled (if any)

getExecutionContext

public org.datanucleus.store.ExecutionContext getExecutionContext()

Description copied from interface: QueryGenerator

Accessor for the ExecutionContext for this query.

Specified by:

getExecutionContext in interface QueryGenerator

Returns:

ExecutionContext

getProperty

public Object getProperty(String name)

Description copied from interface: QueryGenerator

Accessor for a property affecting the query compilation. This can be something like whether there is an OR in the filter, which can then impact on the type of SQL used.

Specified by:

getProperty in interface QueryGenerator

Parameters:

name - The property name

Returns:

Its value

isPrecompilable

public boolean isPrecompilable()

Accessor for whether the query is precompilable (doesn't need to know parameter values to be able to compile it).

Returns:

Whether the query is precompilable and hence cacheable

setNotPrecompilable

protected void setNotPrecompilable()

getParameterNameByPosition

public Map<Integer,String> getParameterNameByPosition()

Convenience accessor for a map of the parameter name keyed by its position. This is only available after

compile

is called.

Returns:

Map of parameter name keyed by position

compile

public void compile()

Method to update the supplied SQLStatement with the components of the specified query. During the compilation process this updates the SQLStatement "compileComponent" to the component of the query being compiled.

compileFrom

protected void compileFrom()

Method to compile the FROM clause of the query into the SQLStatement.

compileFilter

protected void compileFilter()

Method to compile the WHERE clause of the query into the SQLStatement.

compileResult

protected void compileResult()

Method to compile the result clause of the query into the SQLStatement. Note that this also compiles

• queries of the candidate (no specified result), selecting the candidate field(s).
• update clauses of queries

validateExpressionForResult

protected void validateExpressionForResult(SQLExpression sqlExpr)

Method that validates that the specified expression is valid for use in a result clause. Throws a NucleusUserException if it finds a multi-value mapping selected (collection, map).

Parameters:

sqlExpr - The SQLExpression

compileGrouping

protected void compileGrouping()

Method to compile the grouping clause of the query into the SQLStatement.

compileHaving

protected void compileHaving()

Method to compile the having clause of the query into the SQLStatement.

compileOrdering

protected void compileOrdering()

Method to compile the ordering clause of the query into the SQLStatement.

compileFromClassExpression

protected void compileFromClassExpression(org.datanucleus.query.expression.ClassExpression clsExpr)

Method to take a ClassExpression (in a FROM clause) and process the candidate and any linked JoinExpression(s), adding joins to the SQLStatement as required.

Parameters:

clsExpr - The ClassExpression

getStatementMappingForNewObjectExpression

protected StatementNewObjectMapping getStatementMappingForNewObjectExpression(NewObjectExpression expr)

Convenience method to convert a NewObjectExpression into a StatementNewObjectMapping. Handles recursive new object calls (where a new object is an arg to a new object construction).

Parameters:

expr - The NewObjectExpression

Returns:

The mapping for the new object

processAndExpression

protected Object processAndExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processAndExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processOrExpression

protected Object processOrExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processOrExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processEqExpression

protected Object processEqExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processEqExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processNoteqExpression

protected Object processNoteqExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processNoteqExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processGteqExpression

protected Object processGteqExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processGteqExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processGtExpression

protected Object processGtExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processGtExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processLteqExpression

protected Object processLteqExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processLteqExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processLtExpression

protected Object processLtExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processLtExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processLiteral

protected Object processLiteral(org.datanucleus.query.expression.Literal expr)

Overrides:

processLiteral in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processPrimaryExpression

protected Object processPrimaryExpression(org.datanucleus.query.expression.PrimaryExpression expr)

Overrides:

processPrimaryExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processParameterExpression

protected Object processParameterExpression(org.datanucleus.query.expression.ParameterExpression expr)

Overrides:

processParameterExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processParameterExpression

protected Object processParameterExpression(org.datanucleus.query.expression.ParameterExpression expr,
                                            boolean asLiteral)

Method to process a parameter expression. The optional argument controls whether we should create this as a parameter or as a literal (i.e the param value is known etc). If the parameter doesn't have its value defined then returns ParameterLiteral otherwise we get an XXXLiteral of the (declared) type of the parameter

Parameters:

expr - The ParameterExpression

asLiteral - Whether to create a SQLLiteral rather than a parameter literal

processInvokeExpression

protected Object processInvokeExpression(org.datanucleus.query.expression.InvokeExpression expr)

Overrides:

processInvokeExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processSubqueryExpression

protected Object processSubqueryExpression(org.datanucleus.query.expression.SubqueryExpression expr)

Overrides:

processSubqueryExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processAddExpression

protected Object processAddExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processAddExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processDivExpression

protected Object processDivExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processDivExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processMulExpression

protected Object processMulExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processMulExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processSubExpression

protected Object processSubExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processSubExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processDistinctExpression

protected Object processDistinctExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processDistinctExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processComExpression

protected Object processComExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processComExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processModExpression

protected Object processModExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processModExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processNegExpression

protected Object processNegExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processNegExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processNotExpression

protected Object processNotExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processNotExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processCastExpression

protected Object processCastExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processCastExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processCaseExpression

protected Object processCaseExpression(org.datanucleus.query.expression.CaseExpression expr)

Overrides:

processCaseExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processIsExpression

protected Object processIsExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processIsExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processIsnotExpression

protected Object processIsnotExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processIsnotExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processInExpression

protected Object processInExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processInExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processNotInExpression

protected Object processNotInExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processNotInExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processCreatorExpression

protected Object processCreatorExpression(org.datanucleus.query.expression.CreatorExpression expr)

Overrides:

processCreatorExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processLikeExpression

protected Object processLikeExpression(org.datanucleus.query.expression.Expression expr)

Overrides:

processLikeExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processVariableExpression

protected Object processVariableExpression(org.datanucleus.query.expression.VariableExpression expr)

Overrides:

processVariableExpression in class org.datanucleus.query.evaluator.AbstractExpressionEvaluator

processUnboundExpression

protected SQLExpression processUnboundExpression(UnboundExpression expr)

replaceParameterLiteral

protected SQLExpression replaceParameterLiteral(ParameterLiteral paramLit,
                                                org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)

Convenience method to return a parameter-based literal using the supplied mapping to replace the provided ParameterLiteral (generated before its type was known).

Parameters:

paramLit - The parameter literal

mapping - Mapping to use

Returns:

The replacement expression

useParameterExpressionAsLiteral

public void useParameterExpressionAsLiteral(SQLLiteral paramLiteral)

Description copied from interface: QueryGenerator

Method to instruct the generator to convert the provided parameter expression to just be a literal using the value of the parameter (hence the statement cannot be precompilable since the value needs to be known).

Specified by:

useParameterExpressionAsLiteral in interface QueryGenerator

Parameters:

paramLiteral - The parameter expression

hasExtension

public boolean hasExtension(String key)

Description copied from interface: QueryGenerator

Accessor for whether the query being generated has the specified extension.

Specified by:

hasExtension in interface QueryGenerator

Parameters:

key - Extension name

Returns:

Whether it is present

getValueForExtension

public Object getValueForExtension(String key)

Description copied from interface: QueryGenerator

Accessor for the value of the specified query extension (or null if not defined).

Specified by:

getValueForExtension in interface QueryGenerator

Parameters:

key - Extension name

Returns:

The value for the extension

getRequiredJoinTypeForAlias

public SQLJoin.JoinType getRequiredJoinTypeForAlias(String alias)

Convenience method to return the required join type for the specified alias. If the table has a join type defined as an extension "datanucleus.query.jdoql.{alias}.join" then this returns the type. Otherwise returns null.

Parameters:

alias - The alias

Returns:

The join type required (if any)

getValueForObjectField

protected Object getValueForObjectField(Object obj,
                                        String fieldName)

Convenience method to return the value of a field of the supplied object. If the object is null then returns null for the field.

Parameters:

obj - The object

fieldName - The field name

Returns:

The field value

getSQLTableMappingForAlias

protected org.datanucleus.store.rdbms.query.QueryToSQLMapper.SQLTableMapping getSQLTableMappingForAlias(String alias)

getSQLTableForAlias

public SQLTable getSQLTableForAlias(String alias)

Description copied from interface: QueryGenerator

Method to return the SQLTable for the specified primary expression "alias".

Specified by:

getSQLTableForAlias in interface QueryGenerator

Parameters:

alias - The alias ("this", fieldName)

Returns:

The SQLTable for this if it exists

getAliasForSQLTable

public String getAliasForSQLTable(SQLTable tbl)

Returns the alias used for the specified SQLTable. If we have a variable "var1" and there is an access to a field also, then we may have entries for "var1" and "var1.field". In this case we return the shortest.

Parameters:

tbl - The table

Returns:

The query name alias for this table

setSQLTableMappingForAlias

protected void setSQLTableMappingForAlias(String alias,
                                          org.datanucleus.store.rdbms.query.QueryToSQLMapper.SQLTableMapping mapping)

hasSQLTableMappingForAlias

protected boolean hasSQLTableMappingForAlias(String alias)

bindVariable

public void bindVariable(String varName,
                         org.datanucleus.metadata.AbstractClassMetaData cmd,
                         SQLTable sqlTbl,
                         org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)

Method to bind the specified variable to the table and mapping.

Specified by:

bindVariable in interface QueryGenerator

Parameters:

varName - Variable name

cmd - Metadata for this variable type

sqlTbl - Table for this variable

mapping - The mapping of this variable in the table

bindVariable

public SQLExpression bindVariable(UnboundExpression expr,
                                  Class type)

Method to bind the specified unbound variable (as cross join) on the assumption that the type is a persistable class.

Specified by:

bindVariable in interface QueryGenerator

Parameters:

expr - Unbound expression

type - The type to bind as

Returns:

The bound expression to use instead

bindParameter

public void bindParameter(String paramName,
                          Class type)

Method to bind the specified parameter to the defined type. If the parameter is already bound (declared in the query perhaps, or bound via an earlier usage) then does nothing.

Specified by:

bindParameter in interface QueryGenerator

Parameters:

paramName - Name of the parameter

type - The type (or subclass)

getTypeOfVariable

public Class getTypeOfVariable(String varName)

Accessor for the type of a variable if already known (declared?).

Specified by:

getTypeOfVariable in interface QueryGenerator

Parameters:

varName - Name of the variable

Returns:

The type if it is known

hasExplicitJoins

public boolean hasExplicitJoins()

Accessor for whether the query has explicit variables. If not then has implicit variables, meaning that they could potentially be rebound later if prematurely bound in a particular way.

Specified by:

hasExplicitJoins in interface QueryGenerator

Returns:

Whether the query has explicit variables

getBooleanExpressionForUseInFilter

protected BooleanExpression getBooleanExpressionForUseInFilter(BooleanExpression expr)

Convenience method to return a boolean expression suitable for using in a filter. Will return the input expression unless it is simply a reference to a field of a class such as in a filter clause like

myBoolField

. In that case we return a boolean like

myBoolField == TRUE

.

Parameters:

expr - The expression to check

Returns:

The expression valid for use in the filter

resolveClass

public Class resolveClass(String className)

Convenience method to resolve a class name.

Specified by:

resolveClass in interface QueryGenerator

Parameters:

className - The class name

Returns:

The class it relates to (if found)