In an esProc table sequence, a single or multiple fields can be used as a primary key. We can make query based on the primary key using some special functions, which can both simplify the code and increase computational performance effectively.
1. find and pfind
Primary keys are common used in database tables. The valu...
2015-02-04 1109 0
0
Table sequences are frequently used in esProc. A table sequence can be retrieved from a database, created based on data in a sequence or another table sequence using new function, or derived by using derive function to add a single or multiple columns to an existing record sequence or table sequence.
1.Create a table s...
2015-01-26 866 0
0
In relational databases, a foreign key is often used to identify the relationship between tables. In esProc, this relationship of correspondence can be expressed by the foreign key field.
1. Computed columns and foreign key fields
T.derive() function is used in esProc to add computed columns to a table sequence, for ex...
2015-01-08 968 0
0
We often need to sort or rank data during data statistics and analysis. The operations include problems like sort sales records according to the dates and rank the results of salespersons for assessing their performance.
1. Sort and rank members in a sequence
In esProc, functions, such as psort, sort, ranki rank, and e...
2014-12-30 931 0
0
It is a common task to group records in a table sequence as needed and to summarize the data in each group during data analysis and statistics. This includes data summarizing like summing up and averaging, as well as the listing of the top n records, and etc. This article will explore how to group and summarize the dat...
2014-12-04 1213 0
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...
2014-11-20 814 0
0
