Class TDAOQuery (unit DAOQuery)
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Inherits from
TDAODataset
TDAOQuery encapsulates a dataset with a result set that is based on an SQL statement.
procedure Execute;
function MacroByName(const Value: string): TParam;
function ParamByName(const Value: string): TParam;
property FilterText :
property MacroChar : Char
property Macros : TParams
property OpenType : TDAOQueryOpenType
property Params : TParams
property SortText :
property SQL : TStrings
property MacroCount : Integer
property ParamCount : Integer
property RecordsAffected : Integer
procedure Execute;
Executes the SQL statement.
Call Execute to execute the INSERT, UPDATE, or DELETE statement with or without parameters.
function MacroByName(const Value: string): TParam;
To set macros at run time by name.
Example:
DAOQuery1.MacroByName('Order').AsString := 'Customer_Id';
function ParamByName(const Value: string): TParam;
To set input parameters at run time by name.
Example:
DAOQuery1.ParamByName('Customer_Name').AsString := Edit1.Text;
property FilterText :
The property FilterText allows to apply the filter to Recordset.
Note
The filters cannot be applied to TDAOTable with OpenType = db_Open_Table.
property MacroChar : Char
The property MacroChar defines symbol, which is used for macro definition.
Note
Do not use ':' symbol, as it is used for definition of parameters of query.
property Macros : TParams
Contains the macroses for a query’s SQL statement.
It is convinient to use macroses, when it is necessary to modify query at runtime.
For example, you can use macroses to change order clause of sql statement:
DAOQuery1.SQL.Text := 'SELECT * FROM Customers ORDER BY %Order';
DAOQuery1.MacroByName('Order').AsString := 'Customer_Id';
property OpenType : TDAOQueryOpenType
OpenType defines type of returned result set.
OpenType is set from the following values:
db_OpenDynaset |
Opening of Recordset such as a dynamic set of records. |
db_OpenSnapshot |
Opening of Recordset such as a static set of records. |
Look at DAO 3.5 help for additional details.
property Params : TParams
Contains the parameters for a query’s SQL statement.
Look at TQuery's help for additional details.
property SortText :
The property SortText sets sort order to Recordset.
Note
Sort order cannot be applied to TDAOTable with OpenType = db_Open_Table.
property SQL : TStrings
Contains the text of the SQL statement to execute for the query.
property MacroCount : Integer
Indicates the current number of macroses for the query.
property ParamCount : Integer
Indicates the current number of query's parameters.
property RecordsAffected : Integer
Returns number of records, which were used by the last call of a method Execute.