category:SQL Assistance

The Standard Method of Transposing Database Tables in JAVA

Sometimes you need to transpose a database table (or a text file) in JAVA before exporting it out. Different types of transposition require different SQL techniques, and at times you have to do low-level programming in JAVA. That is quite difficult. As esProc that serves as JAVA class library supports dynamic scripting...

2015-12-14 68 0 0

esProc Assists SQL with the Non-Equi-Grouping

In SQL, usually we can only group a table automatically according to its own filed(s). When the grouping criterion comes from another table, or is an external parameter or a conditional list, SQL has to handle the grouping in a very roundabout way. Some cases even require the dynamic criteria, which need to be generate...

2015-09-29 20 0 0

esProc Assists SQL with Sorting in a Fixed Order

Usually SQL is merely able to sort data by one or more certain fields. When it comes to sorting by a list, the only choice is to use decode or union. But with a long list, the SQL statement will be lengthy. If the items of the list are parameters representing unfixed values, usually a temporary table needs to be create...

2015-09-25 20 0 0

Examples of esProc’s Assisting in Dynamic-Column-SQL Computations

The SQL implemented by database vendors can be used to write dynamic statements. But since it’s inconvenient to perform set operations and order-related computations in SQL, usually you must resort to the high-level languages to handle the dynamic-column computations, which leads to a cumbersome process of doing these ...

2015-08-31 16 0 0

The Standard esProc Method of Assisting SQL-style Transposition

In many cases SQL is used to implement a transposition algorithm, such as static/dynamic transposition, natural/inverse transposition, single-/multi-group data transposition, transposition after data alignment/complementing and transposition with/without computed columns. There are different SQL implementations for dif...

2015-08-27 20 0 0

How esProc Assists Writing SQL Queries

esProc can simplify complex SQL-style queries using ordered sets, object-style access and stepwise computation. Usually there are two ways in which esProc is used: an independent one and one requiring integration with Java. Now let’s look at the first one through an example.   The sales table stores several years ...

2015-07-30 44 0 0

esProc Simplifies Order-related SQL-style Computations: Examples

It is difficult for SQL to handle order-related computations, for it does not support ordered sets. But as these computations are very common in real-world business, there are a lot of online discussions related to them. For example: http://stackoverflow.com/questions/29750567/count-several-rows-as-one-if-the-next-row-...

2015-06-25 18 0 0

esProc Helps to Compose Dynamic SQL

It is not uncommon in actual business to tackle complex computational problems by composing dynamic SQL. The skill has generated a lot of discussion across online IT forums. Here are links to some of the questions around it: http://bbs.csdn.net/topics/390876591 http://bbs.csdn.net/topics/390981627 https://www.linkedin....

2015-06-09 17 0 0