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java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.sql.QSqlResult
public abstract class QSqlResult
The QSqlResult class provides an abstract interface for accessing data from specific SQL databases.
Normally, you would use QSqlQuery instead of QSqlResult, since QSqlQuery provides a generic wrapper for database-specific implementations of QSqlResult.
If you are implementing your own SQL driver (by subclassing QSqlDriver), you will need to provide your own QSqlResult subclass that implements all the pure virtual functions and other virtual functions that you need.
Nested Class Summary | |
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static class |
QSqlResult.BindingSyntax
This enum type specifies the different syntaxes for specifying placeholders in prepared queries. |
static class |
QSqlResult.VirtualHookOperation
Press link for info on QSqlResult.VirtualHookOperation |
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter |
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QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I> |
Constructor Summary | |
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protected |
QSqlResult(QSqlDriver db)
Creates a QSqlResult using database driver db. |
Method Summary | |
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protected void |
addBindValue(java.lang.Object val,
QSql.ParamType type)
Binds the value val of parameter type type to the next available position in the current record (row). |
protected void |
addBindValue(java.lang.Object val,
QSql.ParamTypeFlag... type)
Binds the value val of parameter type type to the next available position in the current record (row). |
protected int |
at()
Returns the current (zero-based) row position of the result. |
protected QSqlResult.BindingSyntax |
bindingSyntax()
Returns the binding syntax used by prepared queries. |
protected void |
bindValue(int pos,
java.lang.Object val,
QSql.ParamType type)
Binds the value val of parameter type type to position pos in the current record (row). |
protected void |
bindValue(int pos,
java.lang.Object val,
QSql.ParamTypeFlag... type)
Binds the value val of parameter type type to position index. |
protected void |
bindValue(java.lang.String placeholder,
java.lang.Object val,
QSql.ParamType type)
Binds the value val of parameter type type to the placeholder name in the current record (row). |
protected void |
bindValue(java.lang.String placeholder,
java.lang.Object val,
QSql.ParamTypeFlag... type)
Binds the value val of parameter type Type to the placeholder name in the current record (row). |
protected QSql.ParamType |
bindValueType(int pos)
Returns the parameter type for the value bound at position pos. |
protected QSql.ParamType |
bindValueType(java.lang.String placeholder)
Returns the parameter type for the value bound with the given placeholder name. |
protected java.lang.Object |
boundValue(int pos)
Returns the value bound at position pos in the current record (row). |
protected java.lang.Object |
boundValue(java.lang.String placeholder)
Returns the value bound by the given placeholder name in the current record (row). |
protected int |
boundValueCount()
Returns the number of bound values in the result. |
protected java.lang.String |
boundValueName(int pos)
Returns the name of the bound value at position pos in the current record (row). |
protected java.util.List<java.lang.Object> |
boundValues()
Returns a vector of the result's bound values for the current record (row). |
protected void |
clear()
Clears the entire result set and releases any associated resources. |
protected abstract java.lang.Object |
data(int i)
Returns the data for field i in the current row as a QVariant. |
protected void |
detachFromResultSet()
|
protected QSqlDriver |
driver()
Returns the driver associated with the result. |
protected boolean |
exec()
Executes the query, returning true if successful; otherwise returns false. |
protected boolean |
execBatch()
Equivalent to execBatch(false). |
protected boolean |
execBatch(boolean arrayBind)
|
protected java.lang.String |
executedQuery()
Returns the query that was actually executed. |
protected abstract boolean |
fetch(int i)
Positions the result to an arbitrary (zero-based) row i. |
protected abstract boolean |
fetchFirst()
Positions the result to the first record (row 0) in the result. |
protected abstract boolean |
fetchLast()
Positions the result to the last record (last row) in the result. |
protected boolean |
fetchNext()
Positions the result to the next available record (row) in the result. |
protected boolean |
fetchPrevious()
Positions the result to the previous record (row) in the result. |
static QSqlResult |
fromNativePointer(QNativePointer nativePointer)
This function returns the QSqlResult instance pointed to by nativePointer |
java.lang.Object |
handle()
Returns the low-level database handle for this result set wrapped in a QVariant or an invalid QVariant if there is no handle. |
protected boolean |
hasOutValues()
Returns true if at least one of the query's bound values is a QSql::Out or a QSql::InOut; otherwise returns false. |
protected boolean |
isActive()
Returns true if the result has records to be retrieved; otherwise returns false. |
protected boolean |
isForwardOnly()
Returns true if you can only scroll forward through the result set; otherwise returns false. |
protected abstract boolean |
isNull(int i)
Returns true if the field at position i in the current row is null; otherwise returns false. |
protected boolean |
isSelect()
Returns true if the current result is from a SELECT statement; otherwise returns false. |
protected boolean |
isValid()
Returns true if the result is positioned on a valid record (that is, the result is not positioned before the first or after the last record); otherwise returns false. |
protected QSqlError |
lastError()
Returns the last error associated with the result. |
protected java.lang.Object |
lastInsertId()
Returns the object ID of the most recent inserted row if the database supports it. |
protected java.lang.String |
lastQuery()
Returns the current SQL query text, or an empty string if there isn't one. |
protected abstract int |
numRowsAffected()
Returns the number of rows affected by the last query executed, or -1 if it cannot be determined or if the query is a SELECT statement. |
protected boolean |
prepare(java.lang.String query)
Prepares the given query for execution; the query will normally use placeholders so that it can be executed repeatedly. |
protected QSqlRecord |
record()
Returns the current record if the query is active; otherwise returns an empty QSqlRecord. |
protected abstract boolean |
reset(java.lang.String sqlquery)
Sets the result to use the SQL statement sqlquery for subsequent data retrieval. |
protected boolean |
savePrepare(java.lang.String sqlquery)
Prepares the given sqlquery, using the underlying database functionality where possible. |
protected void |
setActive(boolean a)
This function is provided for derived classes to set the internal active state to a. |
protected void |
setAt(int at)
This function is provided for derived classes to set the internal (zero-based) row position to at. |
protected void |
setForwardOnly(boolean forward)
Sets forward only mode to forward. |
protected void |
setLastError(QSqlError e)
This function is provided for derived classes to set the last error to e. |
protected void |
setNumericalPrecisionPolicy(QSql.NumericalPrecisionPolicy policy)
|
protected void |
setQuery(java.lang.String query)
Sets the current query for the result to query. |
protected void |
setSelect(boolean s)
This function is provided for derived classes to indicate whether or not the current statement is a SQL SELECT statement. |
protected abstract int |
size()
Returns the size of the SELECT result, or -1 if it cannot be determined or if the query is not a SELECT statement. |
Methods inherited from class com.trolltech.qt.QtJambiObject |
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dispose, disposed, finalize, reassignNativeResources, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
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blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread |
Methods inherited from class java.lang.Object |
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clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
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disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
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protected QSqlResult(QSqlDriver db)
Creates a QSqlResult using database driver db. The object is initialized to an inactive state.
Method Detail |
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protected final void addBindValue(java.lang.Object val, QSql.ParamTypeFlag... type)
Binds the value val of parameter type type to the next available position in the current record (row).
protected final void addBindValue(java.lang.Object val, QSql.ParamType type)
Binds the value val of parameter type type to the next available position in the current record (row).
protected final int at()
Returns the current (zero-based) row position of the result. May return the special values QSql::BeforeFirstRow or QSql::AfterLastRow.
protected final QSql.ParamType bindValueType(int pos)
Returns the parameter type for the value bound at position pos.
protected final QSql.ParamType bindValueType(java.lang.String placeholder)
Returns the parameter type for the value bound with the given placeholder name.
protected final QSqlResult.BindingSyntax bindingSyntax()
Returns the binding syntax used by prepared queries.
protected final java.lang.Object boundValue(int pos)
Returns the value bound at position pos in the current record (row).
protected final java.lang.Object boundValue(java.lang.String placeholder)
Returns the value bound by the given placeholder name in the current record (row).
protected final int boundValueCount()
Returns the number of bound values in the result.
protected final java.lang.String boundValueName(int pos)
Returns the name of the bound value at position pos in the current record (row).
protected final java.util.List<java.lang.Object> boundValues()
Returns a vector of the result's bound values for the current record (row).
protected final void clear()
Clears the entire result set and releases any associated resources.
protected final void detachFromResultSet()
protected final QSqlDriver driver()
Returns the driver associated with the result. This is the object that was passed to the constructor.
protected final boolean execBatch()
Equivalent to execBatch(false).
protected final boolean execBatch(boolean arrayBind)
protected final java.lang.String executedQuery()
Returns the query that was actually executed. This may differ from the query that was passed, for example if bound values were used with a prepared query and the underlying database doesn't support prepared queries.
protected final boolean hasOutValues()
Returns true if at least one of the query's bound values is a QSql::Out or a QSql::InOut; otherwise returns false.
protected final boolean isActive()
Returns true if the result has records to be retrieved; otherwise returns false.
protected final boolean isForwardOnly()
Returns true if you can only scroll forward through the result set; otherwise returns false.
protected final boolean isSelect()
Returns true if the current result is from a SELECT statement; otherwise returns false.
protected final boolean isValid()
Returns true if the result is positioned on a valid record (that is, the result is not positioned before the first or after the last record); otherwise returns false.
protected final QSqlError lastError()
Returns the last error associated with the result.
protected final java.lang.String lastQuery()
Returns the current SQL query text, or an empty string if there isn't one.
protected final void setNumericalPrecisionPolicy(QSql.NumericalPrecisionPolicy policy)
protected final void bindValue(int pos, java.lang.Object val, QSql.ParamTypeFlag... type)
protected void bindValue(int pos, java.lang.Object val, QSql.ParamType type)
Binds the value val of parameter type type to position pos in the current record (row).
protected final void bindValue(java.lang.String placeholder, java.lang.Object val, QSql.ParamTypeFlag... type)
Note that binding an undefined placeholder will result in undefined behavior.
protected void bindValue(java.lang.String placeholder, java.lang.Object val, QSql.ParamType type)
Binds the value val of parameter type type to the placeholder name in the current record (row).
Note that binding an undefined placeholder will result in undefined behavior.
protected abstract java.lang.Object data(int i)
Returns the data for field i in the current row as a QVariant. This function is only called if the result is in an active state and is positioned on a valid record and i is non-negative. Derived classes must reimplement this function and return the value of field i, or QVariant if it cannot be determined.
protected boolean exec()
Executes the query, returning true if successful; otherwise returns false.
protected abstract boolean fetch(int i)
Positions the result to an arbitrary (zero-based) row i.
This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the row i, and call setAt with an appropriate value. Return true to indicate success, or false to signify failure.
protected abstract boolean fetchFirst()
Positions the result to the first record (row 0) in the result.
This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the first record, and call setAt with an appropriate value. Return true to indicate success, or false to signify failure.
protected abstract boolean fetchLast()
Positions the result to the last record (last row) in the result.
This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the last record, and call setAt with an appropriate value. Return true to indicate success, or false to signify failure.
protected boolean fetchNext()
Positions the result to the next available record (row) in the result.
This function is only called if the result is in an active state. The default implementation calls fetch with the next index. Derived classes can reimplement this function and position the result to the next record in some other way, and call setAt with an appropriate value. Return true to indicate success, or false to signify failure.
protected boolean fetchPrevious()
Positions the result to the previous record (row) in the result.
This function is only called if the result is in an active state. The default implementation calls fetch with the previous index. Derived classes can reimplement this function and position the result to the next record in some other way, and call setAt with an appropriate value. Return true to indicate success, or false to signify failure.
public java.lang.Object handle()
Returns the low-level database handle for this result set wrapped in a QVariant or an invalid QVariant if there is no handle.
Warning: Use this with uttermost care and only if you know what you're doing.
Warning: The handle returned here can become a stale pointer if the result is modified (for example, if you clear it).
Warning: The handle can be NULL if the result was not executed yet.
The handle returned here is database-dependent, you should query the type name of the variant before accessing it.
This example retrieves the handle for a sqlite result:
QSqlQuery query = ... QVariant v = query.result()->handle(); if (v.isValid() && qstrcmp(v.typeName(), "sqlite3_stmt*")) { // v.data() returns a pointer to the handle sqlite3_stmt *handle = *static_cast<sqlite3_stmt **>(v.data()); if (handle != 0) { // check that it is not NULL ... } }
This snippet returns the handle for PostgreSQL or MySQL:
if (v.typeName() == "PGresult*") { PGresult *handle = *static_cast<PGresult **>(v.data()); if (handle != 0) ... } if (v.typeName() == "MYSQL_STMT*") { MYSQL_STMT *handle = *static_cast<MYSQL_STMT **>(v.data()); if (handle != 0) ... }
protected abstract boolean isNull(int i)
Returns true if the field at position i in the current row is null; otherwise returns false.
protected java.lang.Object lastInsertId()
Returns the object ID of the most recent inserted row if the database supports it. An invalid QVariant will be returned if the query did not insert any value or if the database does not report the id back. If more than one row was touched by the insert, the behavior is undefined.
Note that for Oracle databases the row's ROWID will be returned, while for MySQL databases the row's auto-increment field will be returned.
protected abstract int numRowsAffected()
Returns the number of rows affected by the last query executed, or -1 if it cannot be determined or if the query is a SELECT statement.
protected boolean prepare(java.lang.String query)
Prepares the given query for execution; the query will normally use placeholders so that it can be executed repeatedly. Returns true if the query is prepared successfully; otherwise returns false.
protected QSqlRecord record()
Returns the current record if the query is active; otherwise returns an empty QSqlRecord.
The default implementation always returns an empty QSqlRecord.
protected abstract boolean reset(java.lang.String sqlquery)
Sets the result to use the SQL statement sqlquery for subsequent data retrieval.
Derived classes must reimplement this function and apply the sqlquery to the database. This function is only called after the result is set to an inactive state and is positioned before the first record of the new result. Derived classes should return true if the query was successful and ready to be used, or false otherwise.
protected boolean savePrepare(java.lang.String sqlquery)
Prepares the given sqlquery, using the underlying database functionality where possible. Returns true if the query is prepared successfully; otherwise returns false.
protected void setActive(boolean a)
This function is provided for derived classes to set the internal active state to a.
protected void setAt(int at)
This function is provided for derived classes to set the internal (zero-based) row position to at.
protected void setForwardOnly(boolean forward)
Sets forward only mode to forward. If forward is true, only fetchNext is allowed for navigating the results. Forward only mode needs much less memory since results do not have to be cached. By default, this feature is disabled.
protected void setLastError(QSqlError e)
This function is provided for derived classes to set the last error to e.
protected void setQuery(java.lang.String query)
Sets the current query for the result to query. You must call reset to execute the query on the database.
protected void setSelect(boolean s)
This function is provided for derived classes to indicate whether or not the current statement is a SQL SELECT statement. The s parameter should be true if the statement is a SELECT statement; otherwise it should be false.
protected abstract int size()
Returns the size of the SELECT result, or -1 if it cannot be determined or if the query is not a SELECT statement.
public static QSqlResult fromNativePointer(QNativePointer nativePointer)
nativePointer
- the QNativePointer of which object should be returned.
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