Preliminary studied the table data today, to summarize the understanding of the table data

A, what is the data table structure
Refers to the structure of the database table structure data
1, with the whole column data as the basic computing unit
2, cannot be operated on a particular value
3, already can't operate on
4, the rows in the table as the "record"
5, in the table column called "fields"
6, in the database, a collection of fields for the table, the set of tables for the database

Second, table structure data feature
1, a field only has a data type
2, use the field name to locate the field (as in the excel spreadsheet structure in the data column number)
3, the total number of all the fields in the table consistent
4, in the name of the table to define table
5, usually with a primary key in a table, the characteristics of the primary key is no null values in each row and duplicate values, the primary key is the record unit of the table, all other fields in the table are built around a primary key, the primary key used to identify the position in the table don't counterparts (like excel spreadsheet structure in the data line number)
6, can have no value in the record, but no value also accounts for one row, where no value in a program is identified as null values, a null value is a person with a computer can identify often needs to do to replace the empty value processing

Three, table structure data advantage
1, almost all of the data analysis tools support table structure data
2, can very easily and integrate different data sources associated data
3, can batch for the large-scale data is calculated, and its speed is greater than the table structure data
4, to establish a relationship between the different tables, let all the different dimensional data table into a complete multidimensional data model
5, can be under the different dimensions of discrete numerical summary of observation
6, most of the table structure of a data processing tool records is operation process rather than the calculation results, so once to record a full, accurate operation process, can be repeated use, can be greatly reduced in traditional Excel worksheets for repetitive work