Excerpt: https:? //Wenda.so.com/q/1513900100217695 src = 170 & q = varchar2% 281% 29% E5% A4% 9A% E5% A4% A7
varchar2 oracle is in a unique type, you can store 0-20 digits (written in English), if the Chinese digital words can only store 10.
Create a test table:
create table test
(id int,
name varchar2(20));
Execution sentence, here is the 21 numbers:
insert into test values (1,'123456789012345678901');
Test Chinese figures:
insert into test values (1, '123456789 11');
The result is identical:
So, varchar2 (20) can store 20 numbers, or ten Chinese.
This section is taken from: https: //www.cnblogs.com/Grand-Jon/p/7389427.html
A, Oracle is varchar2 type
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Our character data stored in an Oracle database is generally used VARCHAR2. VARCHAR2 both points PL / SQL Data Types of variable type, Oracle Database field type can be divided in different scenarios of different maximum length.
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In the Oracle Database, VARCHAR2 field type, a maximum value of 4000; PL / SQL variables in VARCHAR2 type, the maximum length of 32767 bytes.
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When VARCHAR2 to fit the information we need to store, came out of Oracle Big Data type LOB (Large Object, large objects).
Two, Oarcle type of LOB
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In Oracle, LOB (Large Object, large object) type of field is now used more and more. Since this type of field capacity (up to 4GB of receiving data), and a table can have multiple fields of this type, very flexible, a very large volume of data applied to a business (e.g., images, archives Wait).
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BLOB and CLOB LOB types are divided into two kinds: BLOB i.e. Binary Large Object (Binary Large Object), adapted for storing non-text byte stream data (such as program, image, video, etc.).
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The CLOB, namely Character Large Object (Character Large Object), are associated with the character set, suitable for storing text data type (such as historical archives, voluminous writings, etc.).