simpleorm.dataset

Class SQuery<T extends SRecordInstance>

java.lang.Object

simpleorm.dataset.SQuery<T>

public class SQuery<T extends SRecordInstance>
extends java.lang.Object

The main Query interface that provides structured queries.

For example:-

Department d100q = session.findOrCreate(Department.DEPARTMENT, "100"); SQuery&lt;Employee&gt; query = new SQuery(Employee.EMPLOYEE) .eq(Employee.DEPARTMENT, d100q) // and .like(Employee.NAME, "%One%") .descending(Employee.SALARY); List&lt;Employee&gt; emps = session.query(query);

This API is a little unusual in that there is only one SQuery instance created, and each of the methods update its state and then return this.

The normal expansion of the query into SQL is performed by SQueryExecute in the SSessionJdbc package. The raw* methods can be used to poke any string into the SQL Where or Order By clauses in the order they appear.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SQuery.Join
static class	SQuery.OrderBy
static class	SQuery.Where

Constructor Summary

Constructors

Constructor and Description
SQuery(SRecordMeta<T> record)
SQuery(SRecordMeta<T> record, SQueryMode queryMode)
SQuery(SRecordMeta<T> record, SQueryMode queryMode, SFieldScalar[] selectList) A new query object that can be .exeuted to produce an SResultSet.
SQuery(SRecordMeta<T> record, SQueryMode queryMode, SSelectMode selectMode)
SQuery(SRecordMeta<T> record, SSelectMode selectMode)

Method Summary

Modifier and Type	Method and Description
SQuery<T>	ascending(SFieldMeta field) rawOrderBy(field.columnName)
SQuery<T>	descending(SFieldMeta field) rawOrderBy(field.columnName) DESC
SQuery<T>	eq(SFieldMeta field, java.lang.Object value) Normally just adds fieldRelopParameter(field, "=", value).
SQuery<T>	eq(SFieldScalar field1, SFieldMeta field2)
SQuery<T>	equivalent(SFieldBoolean field, boolean value) True if boolean field == writeFieldValue(value).
SQuery<T>	fieldQuery(SFieldScalar field, java.lang.String clause) Generates field clause, ie the clause string is poked literally into the query.
SQuery<T>	fieldRelopParameter(SFieldScalar field, java.lang.String relop, java.lang.Object value) Generates field relop ? and then subsequently sets the parameter value.
SQuery<T>	fieldRelopParameter(SFieldScalar field1, java.lang.String relop, SFieldScalar field2) Generates field1 relop field2
SQuery<T>	ge(SFieldScalar field, double value)
SQuery<T>	ge(SFieldScalar field, int value)
SQuery<T>	ge(SFieldScalar field, long value)
SQuery<T>	ge(SFieldScalar field, java.lang.Object value) Just adds fieldRelopParameter(field, ">=", value)
SQuery<T>	ge(SFieldScalar field1, SFieldMeta field2)
java.util.Set<SFieldReference>	getJoinFields()
java.util.List<SQuery.Join>	getJoins()
java.util.Map<SRecordMeta<?>,SSelectMode>	getJoinTables()
long	getLimit()
long	getOffset()
SQuery.OrderBy	getOrderBy()
SQueryMode	getQueryMode()
java.util.ArrayList<java.lang.Object>	getQueryParameters()
java.lang.String	getRawSql()
SRecordMeta<T>	getRecordMeta()
SFieldScalar[]	getSelectList()
SQuery.Where	getWhere()
SQuery<T>	gt(SFieldScalar field, double value)
SQuery<T>	gt(SFieldScalar field, int value)
SQuery<T>	gt(SFieldScalar field, long value)
SQuery<T>	gt(SFieldScalar field, java.lang.Object value) Just adds fieldRelopParameter(field, ">", value)
SQuery<T>	gt(SFieldScalar field1, SFieldMeta field2)
SQuery<T>	in(SFieldScalar field, java.lang.Object... values) Use or clause to simulate the in clause
SQuery<T>	isFalse(SFieldBoolean field)
SQuery<T>	isNotNull(SFieldMeta field) Just adds fieldQuery(field, "IS NULL")
SQuery<T>	isNull(SFieldMeta field) Just adds fieldQuery(field, "IS NULL")
SQuery<T>	isTrue(SFieldBoolean field) shortcut for equivalent(field, true);
SQuery<T>	join(SFieldReference<?> reference) Join to another table, based on the specified reference that is in the query table.
SQuery<T>	join(SFieldReference<?> reference, SSelectMode selectMode)
SQuery<T>	le(SFieldScalar field, double value)
SQuery<T>	le(SFieldScalar field, int value)
SQuery<T>	le(SFieldScalar field, long value)
SQuery<T>	le(SFieldScalar field, java.lang.Object value) Just adds fieldRelopParameter(field, "<=", value)
SQuery<T>	le(SFieldScalar field1, SFieldMeta field2)
SQuery<T>	like(SFieldScalar field, java.lang.Object value) Just adds fieldRelopParameter(field, "like", value)
SQuery<T>	lt(SFieldScalar field, double value)
SQuery<T>	lt(SFieldScalar field, int value)
SQuery<T>	lt(SFieldScalar field, long value)
SQuery<T>	lt(SFieldScalar field, java.lang.Object value) Just adds fieldRelopParameter(field, "<", value)
SQuery<T>	lt(SFieldScalar field1, SFieldMeta field2)
SQuery<T>	ne(SFieldMeta field, java.lang.Object value) Just adds fieldRelopParameter(field, "<>", value).
SQuery<T>	ne(SFieldScalar field1, SFieldMeta field2)
SQuery<T>	rawJoin(java.lang.String sqlJoin, java.lang.Object... parameters) Add a join to the join statement.
SQuery<T>	rawOrderBy(SFieldMeta field, boolean ascending)
SQuery<T>	rawOrderBy(java.lang.String raw) Add a clause to the OrderBy statement, eg.
SQuery<T>	rawPredicate(java.lang.String predicate, java.lang.Object... parameters) Add predicate to the where class, eg.
SQuery	rawSql(java.lang.String rawSelectSql, java.lang.Object... parameters) Just specifies the entire SQL statement, including the Select.
SQuery<T>	setLimit(long lim) Set limit
SQuery<T>	setOffset(long off) Set offset
java.lang.String	toString() See SSession.queryToString for a fuller print out.

Methods inherited from class java.lang.Object

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

Constructor Detail

SQuery

public SQuery(SRecordMeta<T> record,
              SQueryMode queryMode,
              SFieldScalar[] selectList)

A new query object that can be .exeuted to produce an SResultSet.

SQuery

public SQuery(SRecordMeta<T> record,
              SSelectMode selectMode)

SQuery

public SQuery(SRecordMeta<T> record,
              SQueryMode queryMode)

SQuery

public SQuery(SRecordMeta<T> record,
              SQueryMode queryMode,
              SSelectMode selectMode)

SQuery

public SQuery(SRecordMeta<T> record)

Method Detail

getRecordMeta

public SRecordMeta<T> getRecordMeta()

setLimit

public SQuery<T> setLimit(long lim)

Set limit

getLimit

public long getLimit()

getOffset

public long getOffset()

setOffset

public SQuery<T> setOffset(long off)

Set offset

rawJoin

public SQuery<T> rawJoin(java.lang.String sqlJoin,
                         java.lang.Object... parameters)

Add a join to the join statement. Spaces before and after statement are added systematically.

rawPredicate

public SQuery<T> rawPredicate(java.lang.String predicate,
                              java.lang.Object... parameters)

Add predicate to the where class, eg. "BUDGET > ?". Not normally called directly.

rawOrderBy

public SQuery<T> rawOrderBy(java.lang.String raw)

Add a clause to the OrderBy statement, eg. "NAME DESC". Commas are added automatically.

rawOrderBy

public SQuery<T> rawOrderBy(SFieldMeta field,
                            boolean ascending)

rawSql

public SQuery rawSql(java.lang.String rawSelectSql,
                     java.lang.Object... parameters)

Just specifies the entire SQL statement, including the Select.

fieldRelopParameter

public SQuery<T> fieldRelopParameter(SFieldScalar field,
                                     java.lang.String relop,
                                     java.lang.Object value)

Generates field relop ? and then subsequently sets the parameter value. Eg.

fieldRelopParameter(Employee.Name, "=", myName)

fieldRelopParameter

public SQuery<T> fieldRelopParameter(SFieldScalar field1,
                                     java.lang.String relop,
                                     SFieldScalar field2)

Generates field1 relop field2

E.g. fieldRelopParameter(Order.QuantityRequired, "=", Order.QuantityReceived)

Mainly useful for Joins.

fieldQuery

public SQuery<T> fieldQuery(SFieldScalar field,
                            java.lang.String clause)

Generates field clause, ie the clause string is poked literally into the query. Eg.

fieldQuery(Employee.Name, "= 'Fred'")

Use fieldRelopParameter instead for parameters determined at run time as blindly concatenating strings is dangerous.

join

public SQuery<T> join(SFieldReference<?> reference)

Join to another table, based on the specified reference that is in the query table. This peforms an eager lookup on the referenced tables, so avoiding the N+1 problem.

Joins only work from the query table to tables directly liked by the reference. It is not currently possible to join a table to itself (eg. Employee.Manager).

Normally the looked up records are also retrieved, although it is possible to specify selectMode = NONE if the join is only for the WHERE clause.

Currently implemented as Inner joins, but will be fixed to be left outer joins.

Note that this is only useful if the number of joined in records is substantial. For example, if there are 1,000 employees in 10 departments, then it is probably faster (and certainly simpler) to retrieve the departments lazily rather than retrieve the fields for the 10 departments 1000 times and throw them away each time.

Note also that Subselects can be used to reference fields in the where clause without introduing outer join issues.

join

public SQuery<T> join(SFieldReference<?> reference,
                      SSelectMode selectMode)

getJoinTables

public java.util.Map<SRecordMeta<?>,SSelectMode> getJoinTables()

getJoinFields

public java.util.Set<SFieldReference> getJoinFields()

getSelectList

public SFieldScalar[] getSelectList()

eq

public SQuery<T> eq(SFieldMeta field,
                    java.lang.Object value)

Normally just adds fieldRelopParameter(field, "=", value).

If field is a reference it recursively expands the foreign keys, and value must be an instance of the same record type.

value must not be null, you need the special case IS NULL test. (It would be possible to optimize this here, but what about field == field where one of them is null -- that would be inconsistent.)

eq

public SQuery<T> eq(SFieldScalar field1,
                    SFieldMeta field2)

equivalent

public SQuery<T> equivalent(SFieldBoolean field,
                            boolean value)

True if boolean field == writeFieldValue(value). Ie. value is converted from bool to "Y"/"N" etc.

isTrue

public SQuery<T> isTrue(SFieldBoolean field)

shortcut for equivalent(field, true);

isFalse

public SQuery<T> isFalse(SFieldBoolean field)

ne

public SQuery<T> ne(SFieldMeta field,
                    java.lang.Object value)

Just adds fieldRelopParameter(field, "<>", value).

Note that there are few methods ne(SfieldMeta, int) etc. This is because 5 relops * 5 data types would require 25 methods! Java 1.5 boxing will (finally) make this unnecessary anyway.

ne

public SQuery<T> ne(SFieldScalar field1,
                    SFieldMeta field2)

isNull

public SQuery<T> isNull(SFieldMeta field)

Just adds fieldQuery(field, "IS NULL")

isNotNull

public SQuery<T> isNotNull(SFieldMeta field)

Just adds fieldQuery(field, "IS NULL")

gt

public SQuery<T> gt(SFieldScalar field,
                    java.lang.Object value)

Just adds fieldRelopParameter(field, ">", value)

gt

public SQuery<T> gt(SFieldScalar field,
                    int value)

gt

public SQuery<T> gt(SFieldScalar field,
                    long value)

gt

public SQuery<T> gt(SFieldScalar field,
                    double value)

gt

public SQuery<T> gt(SFieldScalar field1,
                    SFieldMeta field2)

lt

public SQuery<T> lt(SFieldScalar field,
                    java.lang.Object value)

Just adds fieldRelopParameter(field, "<", value)

lt

public SQuery<T> lt(SFieldScalar field,
                    int value)

lt

public SQuery<T> lt(SFieldScalar field,
                    long value)

lt

public SQuery<T> lt(SFieldScalar field,
                    double value)

lt

public SQuery<T> lt(SFieldScalar field1,
                    SFieldMeta field2)

le

public SQuery<T> le(SFieldScalar field,
                    java.lang.Object value)

Just adds fieldRelopParameter(field, "<=", value)

le

public SQuery<T> le(SFieldScalar field,
                    int value)

le

public SQuery<T> le(SFieldScalar field,
                    long value)

le

public SQuery<T> le(SFieldScalar field,
                    double value)

le

public SQuery<T> le(SFieldScalar field1,
                    SFieldMeta field2)

ge

public SQuery<T> ge(SFieldScalar field,
                    java.lang.Object value)

Just adds fieldRelopParameter(field, ">=", value)

ge

public SQuery<T> ge(SFieldScalar field,
                    int value)

ge

public SQuery<T> ge(SFieldScalar field,
                    long value)

ge

public SQuery<T> ge(SFieldScalar field,
                    double value)

ge

public SQuery<T> ge(SFieldScalar field1,
                    SFieldMeta field2)

in

public SQuery<T> in(SFieldScalar field,
                    java.lang.Object... values)

Use or clause to simulate the in clause

like

public SQuery<T> like(SFieldScalar field,
                      java.lang.Object value)

Just adds fieldRelopParameter(field, "like", value)

ascending

public SQuery<T> ascending(SFieldMeta field)

rawOrderBy(field.columnName)

descending

public SQuery<T> descending(SFieldMeta field)

rawOrderBy(field.columnName) DESC

toString

public java.lang.String toString()

See SSession.queryToString for a fuller print out.

Overrides:

toString in class java.lang.Object

getQueryParameters

public java.util.ArrayList<java.lang.Object> getQueryParameters()

getJoins

public java.util.List<SQuery.Join> getJoins()

getOrderBy

public SQuery.OrderBy getOrderBy()

getWhere

public SQuery.Where getWhere()

getQueryMode

public SQueryMode getQueryMode()

getRawSql

public java.lang.String getRawSql()