It is difficult to perform inter-row computation of inconsecutive summaries in Excel due to the fact that usually all formulas should be entered by hand, which is not only troublesome but also easy to get wrong. This is because Excel lacks a smart adjustment mechanism and only supports copying formulas mechanically acc...
2014-11-26 156 0
During database application development, we often need to handle complicated SQL-style computations. One of them is the ungrouping, that is, the opposite process of grouping and summarizing which requires, for example, splitting each record into multiple records. We cannot realize the operation in SQL without taking gr...
2014-11-25 100 0
Data sorting by a specified order is one of the complicated SQL-style computations we often need to deal with during the database application development. The computation requires that data be sorted by a specified order rather than in ascending or descending order. For example, sort data according to the order of 2,3,...
2014-11-24 120 0
MongoDB doesn’t support the complex subquery which can only be realized by retrieving the data out first and then performing further computation. The operation is the same complex even if Java or other programming languages are used to write the program. In view of this, we can consider using esProc to help MongoDB wit...
2014-11-21 198 0
In Related Computing in esProc – Data Grouping and Summarizing, we learned how to group data in a table as needed and to summarize the grouped data. Please note that, in data grouping and summarizing, data will be grouped by a single or multiple fields or an expression in ascending order based on equivalent values. Ali...
2014-11-20 163 0
In Excel, formulas can be automatically worked out according to their relative positions while being copied. This works well in continuous cells, but formulas are usually wrong when the operation is performed in incontinuous cells. The computation between multilayered summaries is the latter case.
It is comparatively e...
2014-11-19 138 0
During database application development, we often need to deal with complicated SQL-style computations. The transposition of rows and columns is one of them. Oracle uses pivot function to realize this computation. The other databases haven’t the counterparts to realize it directly, which makes the corresponding code di...
2014-11-19 118 0
The operation of getting the top N rows of data is common, such as the biggest salary raise of each employee, the three lowest scores in playing golf and the five days of each month when each product has its biggest sales. SQL resorts to advanced techniques, like window functions and keep/top/row number, to solve this ...
2014-11-18 128 0
There is a type of text files that they are too big to be entirely loaded into the memory, yet as the data have been sorted by a certain column and if they are imported in groups according to this column, they can be all put into the memory for computing. These text files include the call detail record of a telecom com...
2014-11-17 97 0
During database application development, we often need to handle complicated SQL-style computations. Data grouping with fixed criteria is just one type of these. It refers to the computation whose grouping criteria not come from the to-be-grouped data, but from the outside, such as another table, the external parameter...
2014-11-14 120 0
In esProc computing, we use constants frequently or sometimes store the data in the cellset directly. In this article, let’s learn the usage of constants in the esProc.
1. Directly using constant in the expressions
Constants can be directly used in the esProc expressions:
2014-11-13 149 0
esProc can be embedded into Java program. So the latter can call the cellset program written in esProc using a way of connection such as JDBC. The method of calling the esProc program is the same as that of calling the stored procedure. The following is a brief introduction to esProc JDBC.
1. Description of the j...
2014-11-12 230 0
It is common to group and summarize data in a spreadsheet in data statistics. Through data manipulation in Excel, we can group, summarize, sort or filter data. But it is complicated to process data which has been grouped and summarized in an Excel spreadsheet, because we need to perform the operation on data block of e...
2014-11-12 132 0
As Java doesn’t directly support dynamically parsing expressions in the text files, the computation can only be realized by splitting strings manually and then writing a recursive program. The whole process requires writing a great amount of code, is complicated and the code is difficult to maintain. With the assistanc...
2014-11-11 141 0
3. A record sequence is the reference of table sequence records
Obviously, if each computation on a table sequence is to produce a new table sequence, a great deal of the memory will be used. For instance, a table sequence, Order_Books, has 50,000 records, and 30,000 records are obtained by query. If new table se...
2014-11-10 208 0