Database Engines:odbc
Configuration using DacSession:setProperty() Professional
After a session object was established, these properties can be either read only or also modified using the :setProperty() method. The assignable properties will influence subsequent operations on that session, like DbCreate() or DbUseArea(). The readonly attributes are either properties determined by the driver or are properties configured by a preceding call to DbeInfo().
Constants for DacSession:setProperty()
| Constant | *) | Data type | Description |
|---|---|---|---|
| ODBCSSN_CONCURRENCY | a | N | ODBC concurrency setting as numeric ID. |
| ODBCSSN_CURRENT_DATABASE | ro | C | String holding database name. |
| ODBCSSN_CURSORTYPE | a | N | ODBC cursor type as numeric ID. |
| ODBCSSN_DATATYPES | ro | C | String of supported data types. |
| ODBCSSN_DBMS_NAME | ro | C | Product name of the database |
| ODBCSSN_DBMS_VERSION | ro | C | Version number of the database as ##.##.#### |
| ODBCSSN_DRIVERODBC_VERSION | a | C | ODBC version of driver |
| ODBCSSN_DROP_BEFORE_CREATE | a | L | Issue DROP before CREATE automatically on DbCreate(). |
| ODBCSSN_INDEX_AUTOOPEN | a | L | If .T., auto open an index for CREATE (XPP->ODBC type mapping). |
| ODBCSSN_LONGDATA_THRESHOLD | a | N | Data length to optimize long data access |
| ODBCSSN_MORE_RESULTS | a | N | number of result set, if more expected |
| ODBCSSN_NATIVE_ERROR_INFO | a | L | Enable NATIVE Error in :getLastMessage(). |
| ODBCSSN_ODBC_TO_XPP | ro | A | Array holding data type mapping information for USE (ODBC->XPP type mapping). |
| ODBCSSN_SCROLLABLE | a | N | Scroll attribute of ODBC cursor as numeric ID. |
| ODBCSSN_SENSITIVITY | a | N | ODBC cursor sensitivity as numeric ID. |
| ODBCSSN_SERVER_NAME | ro | C | Name of the data server or service |
| ODBCSSN_SQLSTATE_INFO | a | L | Include SQLSTATE in :getLastMessage(). |
| ODBCSSN_TIMESTAMP_AS_DATE | a | L | map SQL timestamps to Xbase++-Date |
| ODBCSSN_USE_CURSOR_LIB | ro | L | Use ODBC cursor library (see DbeInfo()). |
| ODBCSSN_XPP_TO_ODBC | ro | A | Array holding data type mapping information |
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ODBCSSN_CONCURRENCY and ODBCDBO_CONCURRENCY
Set the concurrency type for the next workarea to open. The value might have been changed after opening a new workarea, see DbInfo().
Values for the ODBC concurrency attribute
| Constant | Description |
|---|---|
| ODBC_CONCUR_LOCK | Pessimistic locking |
| ODBC_CONCUR_READONLY | No write, no locking |
| ODBC_CONCUR_ROWVER *) | Optimistic locking, cheapest method |
| ODBC_CONCUR_VALUES | Optimistic locking, if rowver not available. |
| ODBC_VALUE_UNCHANGED | The attribute is not changed, that means that the call to the respective API is skipped. |
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ODBCSSN_CURRENT_DATABASE
The name of the database the session is connected to. In case of a file-based ODBC driver, this usually is a directory or the full qualified filename of the data file.
ODBCSSN_CURSORTYPE (and ODBCDBO_CURSORTYPE)
Set the cursor type for the next workarea to open. The cursor type can have a different value after opening a new workarea, see DbInfo().
Values for the ODBC cursor type
| Constant | Description |
|---|---|
| ODBC_CURSOR_AUTOMATCH *) | Match cursor type depending on ODBC driver. |
| ODBC_CURSOR_DYNAMIC | Result set reflects all changes. |
| ODBC_CURSOR_FORWARD_ONLY | Cursor skips forward only. |
| ODBC_CURSOR_KEYSET | Cursor rows are determined by keyset. |
| ODBC_CURSOR_STATIC | Result set is a snapshot copy. |
| ODBC_VALUE_UNCHANGED | The attribute is not changed, that means that the call to the respective API is skipped. |
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ODBCSSN_DATATYPES
A string containing all Xbase++ data type characters which are supported by this session.
ODBCSSN_DBMS_NAME
Returns the name or the product name of the database management system which is currently connected to that session.
ODBCSSN_DBMS_VERSION
Returns the version of the database management system which is currently connected to that session as a formatted string using the picture ##.##.####.
ODBCSSN_DRIVERODBC_VERSION
Returns the ODBC version fo the driver. This version depicts the version of ODBC the driver was programmed for. It is used inside of ODBCDBE to work with drivers of different ODBC versions. The value can be modified in case a driver does not work correctly on the version level reported. The value is of the data type string and is formatted as ##.##.
ODBCSSN_DROP_BEFORE_CREATE
The DbCreate() function usually destroys the table (and it's content!) without warning before creating a new table. If this is not desired, set ODBCSSN_DROP_BEFORE_CREATE to .F.
ODBCSSN_INDEX_AUTOOPEN
Auto-opening an index in the context of SQL is handled as follows: If an SELECT - statement having an ORDER BY clause was passed to dbUseArea(), the expression of the ORDER BY clause is used as the index expression. Otherwise, the catalog is queried for the first known index expression. This index will be open after dbUseArea().
ODBCSSN_LONGDATA_THRESHOLD
Long data are data that can be of variable length, and therefore need special attention on read and on write. The ODBCDBE will handle long data of the length up to ODBCSSN_LONGDATA_THRESHOLD byte like fixed data. Changing this value might be necessary to either optimize data access or to turn off the special handling because the ODBC driver is not capable of handling variable length data in every case.
ODBCSSN_MORE_RESULTS
If more than one result set is expected for an SQL command, it is possible to determine which result set to retrieve in the workarea by setting this property. The numbering of result sets starts with 1.
ODBCSSN_NATIVE_ERROR_INFO
The native SQL error will be included in the form like
[-4]
ODBCSSN_ODBC_TO_XPP
This is the data type mapping used on USE.
ODBCSSN_SCROLLABLE and ODBCDBO_SCROLLABLE
Set the scrollability of the cursor for the next workarea to open. The value might have been changed after opening a new workarea, see DbInfo().
Values for the scrollability attribute
| Constant | Description |
|---|---|
| ODBC_NONSCROLLABLE | Cursor can scroll forward only |
| ODBC_SCROLLABLE *) | Cursor can scroll in all directions |
| ODBC_VALUE_UNCHANGED | The attribute is not changed, that means that the call to the respective API is skipped. |
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ODBCSSN_SENSITIVITY and ODBCDBO_SENSITIVITY Set the sensitivity of the cursor for the next workarea to open. The value might have been changed after opening a new workarea, see DbInfo().
Values for the sensitivity attribute
| Constant | Description |
|---|---|
| ODBC_INSENSITIVE | Don't detect changes of other cursors. |
| ODBC_SENSITIVE | Detect changes of other cursors. |
| ODBC_UNSPECIFIED *) | Don't care if changes can occur. |
| ODBC_VALUE_UNCHANGED | The attribute is not changed, that means that the call to the respective API is skipped. |
ODBCSSN_SERVER_NAME
Returns the name of the server the DBMS is running on. Some drivers return the network name of the server (ie. MS-SQL Server), some the name of the database service (ie. Oracle).
ODBCSSN_SQLSTATE_INFO
The SQL state will be included in the form like
[HY002]
ODBCSSN_TIMESTAMP_AS_DATE
Map all SQL-timestamp types (ie.DATETIME, TIMESTAMP etc.) to Xbase++ - Date (XPP_DATE or Valtype(x)=="D"). If the individual remapping of data types using DbInfo() goal is to map timestamps as date, it is simpler to set this session property. Note: If a timestamp is mapped to a date, only the date-part is accessible, the time-part cannot be read or written.
ODBCSSN_USE_CURSOR_LIB
Check if the cursor library could be used if it was configured by DbeInfo(COMPONENT_DICTIONARY, ODBCDBE_USE_CURSOR_LIB) before creating this session.
ODBCSSN_XPP_TO_ODBC
This is the data type mapping used on DbCreate().
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