types of database

1,Database backup TypesAccording to the database size backup, there are four types, respectively applied to different occasions, the following brief introduction:1.1Full BackupThis is the way most people use it to back up the entire database, including all database objects,

Desc table name; show columns from table name; Describe table name; show create table table name; Use information_schemaselect * from columns where table_name = 'table name'; write down: Show databases; You can also Use information_schema Select table_schema, table_name from tables where table_schema = 'database name'Use Database Name; show tables; the original unique index ak_pas_name (pac_name) in the

In doing a CMS, mainly input articles these, there is an article has more than 10 pages, the Content field in the database is the text class, with a rich text editor directly into the field, the result is beyond the length of ... Is there any way to solve it? Reply content: In doing a CMS, mainly input articles these, there is an article has more than 10 pages, the Content field in the database is the

clear, be sure to read this article, but also in the future reconstruction of the work of the correction, otherwise, sooner or later, the problem will come to your side. second, the way to reconstruct the tableLet's not talk about the other, just the way to rebuild the table. As follows 1, to ensure that all table fields, field types, and lengths are exactly the same, I generally do not recommend using the CTAs method to recreate the table. 2. Gene

Tags: Store price har MySQL enumeration oat mysq text DetailWhether it is in the small, free database space or large e-commerce site, reasonable design table structure, make full use of space is very necessary. This requires that we have a good understanding of the common data types of the database system. Below I will write a little bit of my experience to share

Two asp tutorials. net database connection tutorial code // Method 1 String strconn2 = system. configuration. configurationmanager. connectionstrings ["connectionstring"]. connectionstring; Sqlconnection conn = new sqlconnection (strconn2 ); If (conn. state! = Connectionstate. open) { Conn. open (); } // Method 2 String strconn = system. configuration. configurationmanager. apps tutorial ettings. get ("connectionstring "); Sql

Generally, classes can be distinguished by numbers or characters. For example, 1, common member 2, Administrator 3, and super administrator. The database stores situations such as 1, 2, and 3. However, after warehouse picking, it is shown that we need to convert it to what others can understand. Therefore, everyone also makes data dictionaries, but I cannot remember the data dictionaries I have done each time, and the method names used for calling are

point precision and decimal places.Dec (% s, % P): decimal (% s, % P ).Numeric (% s, % P): decimal (% s, % P ). Double: Double precision.Double Precision: Float (53 ).Float (% N): % n = 1 ~ 53.Real: Float (24 ). Image. INT: from-2 ^ 31 ~ 2 ^ 31-1 integer data (all numbers ).Integer: Int.Tinyint: Money: the currency data value ranges from-2 ^ 63 ~ 2 ^ 63-1, accurate to 10 thousandth of the currency unit.Smallmoney: the monetary data value is between-214,748.3648 and + 214.748, 3647, preci

-defined table structure query performance is not high, and the lack of unified query syntax. Graph Database (graph) Neo4j, Infogrid, Infinite Graph Social networks, referral systems, and more. Focus on building a relationship map Graph structure Using graph structure correlation algorithm. such as shortest path addressing, N-degree relationship lookup, etc. Many times need to calculate the entire graph

DB2. The latest release of the new DB2 6.1, management and tuning tools for greater excellence and ease of use. The DB2 can be run on an Intel architecture or on an IBM s/390 mainframe computer. If your industry is particularly praised for IBM machines, it is recommended that you study IBM DB2. There are two versions of DB2: Workgroup Edition and Enterprise Edition. The Workgroup Edition is $999 per server, plus $249 per concurrent user. And the Enterprise Edition is $12500 per CPU, unlimited c

Data | Database Summary: This paper discusses the method and function realization of using ASP to access DBF, DBC, MDB, Excel, SQL Server data, and finally gives an example of accessing Excel database by using the function provided in this paper, which has strong practical meaning for enterprise data reuse and sharing. Keywords: ASP database access, Dbf,dbc,md

Second, connect the database and open the data table Different database connection methods are not the same (that is, the establishment of connection instance method is not the same), once the establishment of the connection instance, the use of Recordset objects to access data from the same method, the following for different types of data, write the correspondi

This article will focus on four types of masql database indexes, how do database indexes be built? The columns that appear in the where and join need to be indexed, but not entirely, because MySQL uses the index only for MySQL indexing is important for the efficient operation of MySQL. Here are a few common types of M

[] Org.hibernate.type.MaterializedBlobType Primitive byte[] Blob Materized_blob Org.hibernate.type.ImageType Primitive byte[] LongVarBinary Image Org.hibernate.type.BinaryType Java.lang.byte[] VARBINARY Wrapper-binary Org.hibernate.type.CharArrayType Char[] VARCHAR Characters, char[] Org.hibernate.type.CharacterArrayType Java.lang.character[] VARCHAR

1.J handling of large text types in DBClarge text data types in Oracle,Clob Long Text type ( not supported in MySQL, using text)Blob binary TypeMySQL Database,Text long Text typeBlob binary TypeRequirements: manipulate long text data in JDBC. Design: Test TableCoding:Saving large text data typesReading large text data typesSaving binary dataRead binary dataMysql:

the storage of large text or picture types again Packagecom. Cherry. Batch;Import Java. IO. File;Import Java. IO. FileInputStream;Import Java. IO. FileReader;Import Java. IO. Reader;Import Java. SQL. Connection;Import Java. SQL. PreparedStatement;Import Java. Util. UUID;Importcom. Cherry. Utils. Dbutils;public class Textsql {public static void main (string[] args) {try {Connection Connection = DBU TILs. Getconn();String sql ="insert into des values (

Is the difference between several character types in the database, which should be known. There is one more thing to mention. varchar and nvarchar are variable-length character types, but will only grow in scope, such as the limit of varchar (20) is 20 bytes, if the value exceeds 20 bytes will be intercepted, and will not automatically grow. So later in the defin

join. SELECT o.id,o.order_number,c.id, c.name from ORDERS O cross JOIN CUSTOMERS C WHERE o.id=1; The results of statement 1 and statement 2 are the same, and the query results are as follows:Two , INNER join (INNER join ) (INNER join): There are two, explicit and implicit, that return data rows in the join table that meet the join criteria and query criteria. (The so-called link table is the database in the form of queries formed in the intermediate

1. Index definitionA database index is like a directory in front of a book, speeding up the query speed of a database. An index is a structure that sorts the values of one or more columns in a database table (for example, the last name (lname) column of an employee table). If you want to find him or her by the name of a particular employee, the index helps you ge

data type (mysql)Int char bit varchar date time datetime textCharacter:Char Normal string (how much is honestly accounted for)Varchar variable string ( how much to use)(characters are said to be the number of characters.) Bytes are said to store the size of the text)(except The ASCLL (0~127) Code series accounts for 1 bytes. The others are two bytes)Text large text does not set length (16kb)Longtext Maximum TextDateTimeDateDatime ( eight bytes )(month, day, minute and second)Common data typesInt