Question: Is it possible to have a trigger invoke code in a running application (either via a register-notify type of thing or by calling entry points of a DLL or…)?

Question: How do I set a default for a date field having sysdate, current_date or date as the value? Answer: To use the current date as a default value in

When you are inserting data into Oracle tables in SQL*Plus using hard-coded string, some of the character fields may contain the ampersand character (&). The following is an example: insert

Although an index is not mandatory on your foreign keys, if they are not indexed you will cause additional locking when certain Data Manipulation Language statements are executed against the

Many programmers create stored procedures out of large bodies of database trigger codes. This has primarily been because while stored procedures are stored in compiled form, database triggers are compiled

In a PL/SQL block, if you are querying a database table, you need to declare data variables to hold column values returned from the query. The variables can be declared

The DBMS_UTILITY.COMPILE_SCHEMA procedure compiles all procedures, functions and packages in the specified schema. DBAs now don’t have to generate the dynamic scripts to recompile the invalid objects in the schema

PL/SQL supports three parameter-passing modes: IN

At some point, you must have encountered a “Snapshot too old” error when running a huge batch transaction. Then you find that you may have to restart the process all

If you are ever trying to write SQL to access SQL server’s system tables, it is often useful to look at SQL Server’s own system stored procedures. You can do

Question: Can you explain the interaction of the RS232 signals (RTS, CTS, DTR, etc.). I need to write a software utility to transmit and receive characters between two computers, but

Question: I need to extract information using WHERE on fields in two different tables: one a text field, the other a numeric field. Both hold only numeric data. How can

Question: I’m writing a select statement to make a table name a variable whose value is set according to a condition: Var tablename;tablename := emp tableselect * from tablename; But

Question: How do I find out if a user has disabled cookies? Answer: To find out if a user has disabled cookies, follow these steps: Set a cookie. Redirect to

Question: Does Informix have a data type similiar to SQL Server’s image or ntext to input paths to link images? Answer: I’d use a CHAR(25) or a VARCHAR field for

Question: Why, after deleting an object I allocated dynamically, is the pointer still there? What exactly have I deleted and what would happen if I assigned a new value to

Question: Does WAP have a concept of IP address? Answer: You can get the gateway IP address and the terminal IP address using HTTP headers. WAP 1.1 currently has no

Question: I have a table in which the key field has a value stored with a percent sign, like ‘1234%’.Using this value, I want to select from another table that

Question: I have installed the version 9.2 of ESQLC, and when I try to run the program in the following manner: esql -e crdb.ec cc -c -I/home/informix/incl/esql crdb.c cc -ocrdb7.exe

Question: How do I concatenate a value in Stored Procedures (e.g., select * from mytable, where mytable.field1 = field that I concatenate)? Answer: If you want to match field1 to

Question: My base class contains this constructor: class Parent { Parent(int a, int b, char* c);}; My derived class contains this constructor: class Child : public Parent { Child(int a);};

Instead of using a META tag to re-direct a URL, simply place this code in place of the old page and a visitor will instantly be taken there. This piece

When you plan your queries, you should avoid the use of wildcard keyword * – which means “retrieve any field” – mainly because it may decrease performances, since the engine

Thanks to the SQL-DMO object model, it’s very easy to list all the available SQL Server 7.0 installations. For example, this code loads all the SQL Servers registered on the

The DateSerial function has an interesting feature: it doesn’t raise errors when you pass it an invalid month or day number. Instead, it evaluates the date as if the arguments

Using the SQL-DMO object model you can programmatically start, stop, pause, and continue the main SQL Server service. In the following code snippet the server is “MyServer”, and “sa” /