Is Oracle Database Case Sensitive?

It is not case-sensitive, keywords, users, passwords, field names, table names, sequence names, trigger names, etc. are not distinguished, we usually enter the table name that is entered casually in case case, field name, keyword case ignores the table name, the field name cannot use keywords, table name, field name can not start with a number, there can be no special symbol in the middle, the length of the field name cannot exceed 30 characters Table name, and the field name definition needs to have meaning. Specific field values are case-sensitive. Scott is a beginner learning user, learners can use Scott to log in to the system, note that after Scott users log in, they can use the database and data tables provided by Oracle, which are provided by Oracle.

Oracle Database Case-Sensitive Issues:

Oracle is not case-sensitive, e.g.

create table tablename(id number);Although there are uppercase and lowercase when writing, there is no distinction in the database.

select * from tablename;That's okay.

select * from tablename;There will be no problem writing this way.

select * from tablename;No problem.

create table "tablename"("id" number);If the table is created in this way, it must be strictly case-sensitive.

select * from "tablename";It is necessary not only to be case-sensitive, but also to be double-quoted to distinguish it from the third query above.

In general, there is no distinction.

However, when it comes to query strings, they are case-sensitive.

For example, if you have a field named name in your table, you want to find someone whose name is xiaoming.

The xiaoming here is case-sensitive.

In addition, the places in the system table, such as the table space, table name, and the name of each object, should be capitalized.

The lower function turns all your uppercase characters into lowercase.

It is also possible to use upper to make all lowercase uppercase.

Usage: select (upper.)'abcd) from duallower usage is the same as above.

Oh, it's a net pick, and it feels the same.

Case-sensitive, not looking at the database, looking at the operating system. For example, windows is case-sensitive. Linux doesn't distinguish between them.

I've used statements that don't distinguish between characters in quotation marks.

Case-insensitive, keywords, users, passwords, field names, table names, sequence names, triggers.

The name is not distinguished, we usually enter the table name with case and casual, field name, keyword case ignore the table name, the field name can not use keywords, the table name, the field name can not use the number start, there can be no special spring beam character in the middle of the table name, the length of the field name can not exceed 30 characters table name, the field name definition needs to have meaning.

Specific field values are case-sensitive. Scott is a beginner learning user, learners can use Scott to log in to the system, note that after Scott users log in, they can use the database and data tables provided by Oracle, which are provided by Oracle.

It is differentiated, and it has been built in the library in the past, but this time I forgot to turn off a property when I generated it with pd9, and I actually had to name the "tablespace" in front of the table in the database every time"."Table name"The form and must be quoted, the case must be recorded, otherwise it will tell me that there is no view, depressed to death So I checked the relevant web page, and the answer is differentiated, but it is necessary to force the distinction when building the table, that is, the double quotation marks are used when the table is built.

Otherwise, oracle has no distinction by default, you use lowercase to create a table, it doesn't matter, oracle automatically converts to uppercase, and then you can use uppercase when you call it. If you want to force case when creating a table, you need to use the upper and lower functions to convert it.

As for the data stored in the table, there is still a distinction, and depositing uppercase is uppercase, and storing lowercase is lowercase, which should be paid attention to when querying. Remember to deal with it next time, pitiful, to "remove the quotation marks" from the fields one by one in hundreds of tables, and use alter table name1 rename to name2 !to remove the quotation marks on the name of the database table (for the name of name2, you don't need to add the namespace :)).