free barcode generator source code in vb.net SQL: The Complete Reference in Software

Paint Code-128 in Software SQL: The Complete Reference

SQL: The Complete Reference
Scanning Code 128 Code Set A In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
Drawing Code-128 In None
Using Barcode drawer for Software Control to generate, create Code 128 Code Set A image in Software applications.
Enter Enter Enter Enter Enter Enter Enter Enter
Read Code128 In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
ANSI/AIM Code 128 Generator In C#.NET
Using Barcode creator for .NET Control to generate, create Code128 image in .NET applications.
Salesperson's new value for new value for new value for Salesperson's new value for new value for new value for
Code 128 Code Set C Maker In Visual Studio .NET
Using Barcode maker for ASP.NET Control to generate, create Code128 image in ASP.NET applications.
Encoding Code 128A In Visual Studio .NET
Using Barcode printer for .NET framework Control to generate, create Code 128B image in VS .NET applications.
Employee Number: 106 Name: Sue Jackson Office: 22 Quota: 175000.00 Employee Number: 104 Name: Joe Smith Office: * Quota: 275000.00
Encoding Code 128 Code Set A In VB.NET
Using Barcode encoder for VS .NET Control to generate, create Code 128B image in Visual Studio .NET applications.
Creating Code-128 In None
Using Barcode printer for Software Control to generate, create Code-128 image in Software applications.
Enter Salesperson's Employee Number: 0 All updates committed.
Making UPC-A In None
Using Barcode drawer for Software Control to generate, create UPC Code image in Software applications.
ECC200 Generator In None
Using Barcode generator for Software Control to generate, create ECC200 image in Software applications.
Based on the user s response to the initial questions, the program generates this dynamic UPDATE statement and prepares it:
Drawing Code 3 Of 9 In None
Using Barcode encoder for Software Control to generate, create Code 3 of 9 image in Software applications.
Printing Bar Code In None
Using Barcode drawer for Software Control to generate, create bar code image in Software applications.
update salesreps set name = , office = , quota = where empl_num =
GTIN - 12 Printer In None
Using Barcode creator for Software Control to generate, create UPC-E Supplement 2 image in Software applications.
Code 39 Extended Generator In Java
Using Barcode maker for Java Control to generate, create Code 39 image in Java applications.
The statement specifies four parameters, and the program allocates a SQLDA big enough to handle four SQLVAR structures. When the user supplies the first set of parameter values, the dynamic UPDATE statement becomes:
Decode Bar Code In .NET Framework
Using Barcode recognizer for .NET Control to read, scan read, scan image in .NET framework applications.
Encode Barcode In None
Using Barcode drawer for Microsoft Word Control to generate, create bar code image in Microsoft Word applications.
update salesreps set name = 'Sue Jackson', office = 22, quota = 175000.00 where empl_num = 106
Painting Barcode In Objective-C
Using Barcode maker for iPad Control to generate, create bar code image in iPad applications.
Generating EAN / UCC - 13 In None
Using Barcode creator for Font Control to generate, create EAN 128 image in Font applications.
and with the second set of parameter values, it becomes:
Encode Bar Code In .NET
Using Barcode generation for ASP.NET Control to generate, create bar code image in ASP.NET applications.
Encoding Code 128 Code Set B In None
Using Barcode creation for Office Word Control to generate, create Code 128A image in Office Word applications.
update salesreps set name = 'Joe Smith', office = NULL, quota = 275000.00 where empl_num = 104
This program is somewhat complex, but it s simple compared to a real generalpurpose database update utility. It also illustrates all of the dynamic SQL features required to dynamically execute statements with a variable number of parameters.
Dynamic Queries
The EXECUTE IMMEDIATE, PREPARE, and EXECUTE statements as described thus far support dynamic execution of most SQL statements. However, they can t support dynamic queries because they lack a mechanism for retrieving the query results. To support
18:
Dynamic SQL *
dynamic queries, SQL combines the dynamic SQL features of the PREPARE and EXECUTE statements with extensions to the static SQL query-processing statements, and adds a new statement. Here is an overview of how a program performs a dynamic query: 1. A dynamic version of the DECLARE CURSOR statement declares a cursor for the query. Unlike the static DECLARE CURSOR statement, which includes a hard-coded SELECT statement, the dynamic form of the DECLARE CURSOR statement specifies the statement name that will be associated with the dynamic SELECT statement. 2. The program constructs a valid SELECT statement in a buffer, just as it would construct a dynamic UPDATE or DELETE statement. The SELECT statement may contain parameter markers like those used in other dynamic SQL statements. 3. The program uses the PREPARE statement to pass the statement string to the DBMS, which parses, validates, and optimizes the statement and generates an application plan. This is identical to the PREPARE processing used for other dynamic SQL statements. 4. The program uses the DESCRIBE statement to request a description of the query results that will be produced by the query. The DBMS returns a column-by-column description of the query results in a SQL Data Area (SQLDA) supplied by the program, telling the program how many columns of query results there are, and the name, data type, and length of each column. The DESCRIBE statement is used exclusively for dynamic queries. 5. The program uses the column descriptions in the SQLDA to allocate a block of memory to receive each column of query results. The program may also allocate space for an indicator variable for the column. The program places the address of the data area and the address of the indicator variable into the SQLDA to tell the DBMS where to return the query results. 6. A dynamic version of the OPEN statement asks the DBMS to start executing the query and passes values for the parameters specified in the dynamic SELECT statement. The OPEN statement positions the cursor before the first row of query results. 7. A dynamic version of the FETCH statement advances the cursor to the first row of query results and retrieves the data into the program s data areas and indicator variables. Unlike the static FETCH statement, which specifies a list of host variables to receive the data, the dynamic FETCH statement uses the SQLDA to tell the DBMS where to return the data. Subsequent FETCH statements move through the query results row by row, advancing the cursor to the next row of query results and retrieving its data into the program s data areas. 8. The CLOSE statement ends access to the query results and breaks the association between the cursor and the query results. This CLOSE statement is identical to the static SQL CLOSE statement; no extensions are required for dynamic queries.
Copyright © OnBarcode.com . All rights reserved.