database-engine | 易学教程

Unable to insert data into MS Access database from Visual C#

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问题 just a beginner in Programing ... I use a class to handle the connectionstring . public class DataBase { public OleDbConnection con = new OleDbConnection(); public OleDbCommand cmd = new OleDbCommand(); public void getConnection() { con.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Project\Database\DataBase.mdb"; } private void btnPrint_Click(object sender, EventArgs e) { DataBase db = new DataBase(); db.getConnection(); string Name = txtCostumerName.Text; string

MySQL database size estimation

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问题 I have an application database with a table for users (1kbyte of data per user based on counting fields * typelength), and about 100 things of the same size belonging to a user (0.5 kbyte per thing), and it is in a "user" table and a "thing" table. That would seem to lead to about 51kbytes of data per user. However, I have heard that for MySQL, I should double it to cover index tables, which would get me to 102kbytes/user Is that true? Are there any other data expansion factors to consider

How to write a simple database engine [closed]

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问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 6 years ago . I am interested in learning how a database engine works (i.e. the internals of it). I know most of the basic data structures taught in CS (trees, hash tables, lists, etc.) as well as a pretty good understanding of compiler theory (and have implemented a very simple interpreter) but I don't understand how to go

What are MySQL database engines? [closed]

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I looked around and found some of the MySQL engines are innodb and MyISAM. Perhaps there are few more. My question is what are these database engines? What are the differences between different MySQL engines? And more importantly, How do I decide which one to use? mysql> SHOW ENGINES; +------------+---------+----------------------------------------------------------------+--------------+------+------------+ | Engine | Support | Comment | Transactions | XA | Savepoints | +------------+---------+----------------------------------------------------------------+--------------+------+------------+

How to write a simple database engine [closed]

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I am interested in learning how a database engine works (i.e. the internals of it). I know most of the basic data structures taught in CS (trees, hash tables, lists, etc.) as well as a pretty good understanding of compiler theory (and have implemented a very simple interpreter) but I don't understand how to go about writing a database engine. I have searched for tutorials on the subject and I couldn't find any, so I am hoping someone else can point me in the right direction. Basically, I would like information on the following: How the data is stored internally (i.e. how tables are represented

What are MySQL database engines? [closed]

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问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed last year . I looked around and found some of the MySQL engines are innodb and MyISAM. Perhaps there are few more. My question is what are these database engines? What are the differences between different MySQL engines? And more importantly, How do I decide which one to use? 回答1: mysql> SHOW

Is There A Database Engine that Allows for Queriable Field Constraint Specified by RegEx?

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问题 I'm looking for a database engine that can handle data constraints specified via RegEx. So in addition to the datatype, I want to be able to control the format of the data. E.g. a varchar(255) field could be further restrained to be like [a-zA-Z0-9 ] . I need the RegEx to be able to be queried too, so I can share those constraints throughout the n-tier system to enforce on several levels. E.g. MySQL allows for querying of information_schema to get meta data, and other database engines have