After reading the next section on resetting all properties, come back and change the color property to all. Notice how the second link is on a new line and has a bullet. What properties do you think were inherited?

$ git diff --cached # difference between HEAD and the index; what # would be committed if you ran "commit" now. $ git diff # difference between the index file and your # working directory; changes that would not # be included if you ran "commit" now. $ git diff HEAD # difference between HEAD and working tree; what # would be committed if you ran "commit -a" now. $ git status # a brief per-file summary of the above.

PRIMARY KEY We are already familiar with the PRIMARY KEY (which we will refer to as PK). In the Chapter 1-2 SQL Data Structure: Table, we learned that it represents the unique key of a table and cannot be repeated. We also reserved a foreshadowing in this chapter to mention that PK is very important for the efficiency of searching for data. The reason will be revealed in this section. When setting the PK for the database, an index is also created, and PRIMARY KEY is used as the index category. The advantage of using this category is that when we use the JOIN to combine two tables together, it will effectively increase the processing speed. You may have noticed that when we are concatenating, it is usually id to id. At this time, the index of PK will take effect, which brings extremely high speed. Therefore, when using JOIN, try to connect with PK to ensure the execution speed!

OpenGIS spatial types

SET