Sometimes, because of project development, some tables in the SQLServer2005 must be synchronized to the Oracle database, which can be read by other systems. Data synchronization between different database types can be implemented using linked
Charvarcharvarchar2 differences: 1. the length of CHAR is fixed, while the length of VARCHAR2 can be changed. For example, the storage string "abc", for CHAR (20 ), it indicates that the characters you store will occupy 20 bytes (including 17 null
Oracle defines string types VARCHAR2 and char specify the length of the usage as follows:VARCHAR2 ( ) is a number between 1~4000 that represents up to 4000 bytes of storage space.char ( ) is a number between 1~2000 that represents up to 2000 bytes
I. Background of the problemProduction environment: Oracle database, hibernate operation defines a table
CREATE TABLE Store_information (ID CHAR () not NULL, name VARCHAR2 (254) Default ", Conte NT CLOB default ', create_time VARCHAR2 default ',
Char varchar varchar2 the difference http://blog.csdn.net/honglei_zh/article/details/7172538Difference:1. The length of the char is fixed, and the length of the VARCHAR2 is changeable, for example, storing the string "abc", for Char (20), which
1. The length of char is fixed, the length of the VARCHAR2 can vary, for example, the storage string "abc", for Char (20), which means that the characters you store will occupy 20 bytes (including 17 null characters), in the database it is occupied
Comparison of data typesChar represents a fixed length, and the longest n-word varchar represents the actual length of the data type, such as: if it is a char type, when you enter a character that is less than the length, then a space is added, but
Oracle basic concepts and comparison with informix
I. ConceptsUser: informix directly uses the user management system of the operating system. Generally, root and informix are used as super operators to manage other users. Oracle has its own user
a varchar,varchar2,nvarchar,nvarchar2All four types belong to the variable-length character type, and the difference between varchar and VARCHAR2 is two bytes for all characters in the latter, and the former only has two bytes for kanji and
Recently, I have dealt with some Oracle character data types. I want to learn from them as follows:
1. First, compare the char and varchar2 types:
Differences:
1. the length of CHAR is fixed, while the length of VARCHAR2 can be changed. For example,
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