- Vytvoril/a D2000 Dev Team, naposledy zmenené okt 25, 2024
DB_UPDATE and DBS_UPDATE actions
DB_UPDATE handleIdent_Int, rowIdent, retCodeIdent_Int [WHERE strExpression_Str [BINDIN varIdent1, varIdent2, ... ]] [ORAHINT hintIdent_Str] DB_UPDATE handleIdent_Int, rowIdent, retCodeIdent_Int [WHERE strExpression_Str [BINDIN structRowIdent]] [ORAHINT hintIdent_Str] DBS_UPDATE dbObjIdent, rowIdent, retCodeIdent_Int [WHERE strExpression_Str [BINDIN varIdent1, varIdent2, ... ]] [TRANS transHandle_Int] [ORAHINT hintIdent_Str] DBS_UPDATE dbObjIdent, rowIdent, retCodeIdent_Int [WHERE strExpression_Str [BINDIN structRowIdent]] [TRANS transHandle_Int] [ORAHINT hintIdent_Str]
DB_UPDATE handleIdent_Int, structIdent, retCodeIdent_Int [ORAHINT hintIdent_Str] DBS_UPDATE dbObjIdent, structIdent, retCodeIdent_Int [TRANS transHandle_Int] [ORAHINT hintIdent_Str]
| handleIdent_Int | in | Identifier of Int type (handle) of the connection with the database (DB_CONNECT). |
| dbObjIdent | in | Reference to an object of Database table type. |
| rowIdent | in | One structure row identifier (a row to update). |
| structIdent | in | Identifier of entire structure (the rows to update). |
| retCodeIdent_Int | out | Return value of Int type - action success. |
| strExpression_Str | in | Expression of String type, which identifies modified rows. If the expression is parameterized, the keyword BINDIN and the values of parameters (structRowIdent or varIdent1, varIdent2, ...) are mandatory. |
| varIdent1, varIdent2, ... | in | List of objects, constants or local variables, which will specify the values of parameters of parameterized SQL expression strExpression_Str. |
| structRowIdent | in | Reference to a row of local variable of Record type or to a row of structured variable. The row's values will specify the values of parameters of parameterized SQL expression strExpression_Str. |
| transHadle_Int | in | Identifier of the Connection to the database. |
| hintIdent_Str | in | Expression of String type that defines Oracle SQL hint. It is used as an instruction for the performance optimizer of SQL command. The value is used without the opening and terminating characters /*+ <orahint> */. The example is mentioned here. |
- Setting the key items in a structure row (
rowIdent) or in the entire structure (structIdent). The setting must be performed before the action DB_UPDATE. The respective items must be marked as the key during the definition of an object of a Table type. Then in the database, a row which key items values are equal to the key items ofrowIdentis found and is modified. The row or structure to be updated must be of a proper type of structure.The values of all key items inrowIdentmust be valid, otherwise the update will fail, end with an error, and %GetLastExtErrorCode() will return error 667. The value of the expression
strExpression_Strwhich represents WHERE clause for the SQL command UPDATE performing a database change. In this case, a key item value is not used.
If the strExpression_Str expression is not specified (or is empty) or the key is not defined when defining a Table type object, the action will return the error _ERR_TRANS_ERROR (11) and the variable _ERR_NR_TRANS_EX will have the value BAD_CONDITION.
Note: we recommend using the version without the strExpression_Str expression - when using the expression, Oracle temporarily locks the updated table as well as all tables into which the updated table has foreign indexes. This can cause a blocked session if another transaction in progress has updated any rows in these tables. The blocking will last until the ongoing transaction is completed.
The advantage of the action DBS_UPDATE during the work with a table is the possibility to leave out its opening and closing (simpler notation).
For D2000 v5.00: A disadvantage of the action DBS_UPDATE is in speed. Each DBS_UPDATE call results in necessity to open and close the database in DBManager - it can be a time-consuming operation and it is a comparatively nonstandard method in term of databases.
The need to open and close the database may be eliminated in the scope of transaction processing so that the command is followed by the parameter
TRANS
For D2000 v6.00 and higher: DBManager optimization (connection recycling, predefined connections) causes, that the action DBS_UPDATE is executes as quick as the action DB_UPDATE and moreover there is saved a time required for execution of the action DB_CONNECT to open the database.
The need to open and close the database may be eliminated in the scope of transaction processing so that the command is followed by the parameter
TRANS
Related pages:
0 komentárov