
SQL PRIMARY KEY
A primary key is used to uniquely identify each row on a table. It can either be part of the actual record itself, or it can be an artificial field (something …
Continue reading
A primary key is used to uniquely identify each row on a table. It can either be part of the actual record itself, or it can be an artificial field (something …
Continue reading
A foreign key is a field (or fields) that points to the primary key of another table. The purpose of the foreign key is to ensure referential integrity of the …
Continue reading
Sometimes we may decide that we need to get rid of a table in the database for some reason. In fact, it would be problematic if we cannot do so because this …
Continue reading
Sometimes we wish to get rid of all the data in a table. One way of doing this is with DROP TABLE, which we saw in the last section. But what if we wish to …
Continue readingIn the previous sections, we have seen how to retrieve information from tables. But how do these rows of data get into these tables in the first place? This is …
Continue readingOnce we have the information in the table, we might find that there is a need to modify the data. To do so, we can use the UPDATE command. The syntax for this …
Continue readingSometimes rather than updating, we wish to get rid of records from the table. To do so, we can use the DELETE FROM command. The syntax for this is DELETE FROM …
Continue readingAbstract: in this instructional exercise, you will find out about the Oracle DUAL table which is a unique table utilized for assessing articulations or calling …
Continue readingSummary: in this tutorial, you will learn how to use the Oracle SELECT statement to query data from a single table. In Oracle, tables are consists of columns …
Continue readingThe Oracle Database is an object-relational database management system created and advertised by Oracle Corporation. The Oracle Database is regularly alluded to …
Continue readingWe will now see how to install MySQL server windows. MySQL server database management is a very important tool for us. We’re going to set up MySQL by simply …
Continue reading