Recently learned SQL in Teradata environment. Here to record the study of the knowledge points, as a record.Directory:
About SQL learning and the online database used
Table Union (join)
SQL Sub-query
Create a new field at select (as, Case time)
Data Grouping (group BY + aggregate function count
c.t_id=d.t_id left joins student A on a.s_id=b.s_id where D.tname= ' Zhang San '; /*dense_rank () */select E.s_id,e.c_id,e.score from (select s_id, c_id, Score,dense_rank () over (partition by c_id ORDER BY s_id) Rank1 from SC) e left joins course C on e.c_id=c.c_id left joins teacher D on c.t_id=d.t_id where D.tname= ' Zhang San '
and e.rank1=1; Select Top 1* from (select s_id, c_id, Score,dense_rank () up (partition by c_id ORDER by s_id) Rank1 from SC E left J
Oin course C on e.c_id=c
Explain basic SQL syntax and SQL syntax
1. Create a database
Create database Name
2. delete a database
Drop database name
3. Back up SQL server
The device that creates the backup data
Use master
Exec sp_addumpdevice 'name', 'new name', 'path'
Start backup
Backup database pub
Label:Error occurred while generating SQL file with power Designer [ERR] 1064-you has an error in your SQL syntax; Check the manual that corresponds t o your MySQL server version for the right syntax to use near ' int not null auto_increment comment ' user ID ', The solution The S
Oracle -- SQL syntax summary and oraclesql syntax Summary
-- Statement block declare v_name varchar2 (30): = 'jack' -- defines the variable begin select v_name from dual; exception when others then dbms_output.put_line ('exception occurred '); end; -- if judge declare v_num1 number; v_num2 number; v_result varchar2 (10); begin if v_num1 is null or v_num2 is null
Label:A few years have not been used MySQL data, today in the use of C # access to the MySQL database is a small episode. Error message: You have a error in your SQL syntax; Check the manual-corresponds to your MySQL server version for the right syntax-use??? Of course, the error message is clearly explained by the syntax
Use? PLACEHOLDER write MySQL query statement, execute error 1 Com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException:You has an error in your SQL syntax; Check the manual, corresponds to your MySQL server version for the right syntax to use near '?,?,?,?) ' At line 1 2 @ sun.reflect.NativeConstructorAccessorImpl.newInstance0 (Native Method) 3 at Sun.reflect.Na
When inserting a very simple SQL statement, MySQL always complains:[SQL] INSERT into ORDER (IdACTIVITY_ID,Order_type,PhoneOrder_amount,Order_state,Pay_type)VALUES(' 4 ',' 2121313 ',' 1 ',' 13552444989 ',' 1 ',' 1 ',' 1 ')[ERR] 1064-you has an error in your SQL syntax; Check the manual, corresponds to your MySQL server
Label:Three ways: LINQ, LAMBDA, SQL syntax 1. Simple LINQ Syntax 1
var ss = from R in Db. Am_recproscheme
Select R;
2
var SS1 = db. Am_recproscheme;
3
String sssql = "SELECT * from Am_recproscheme"; 2. Query with where 1
var ss = from R in Db. Am_
The syntax is as follows:1. Description: copy a table (only copy structure, source table name: a new table name: B) (access available)Method 1: Select * into B from a where 1 Method 2: Select top 0 * into B from
2. Description: copy a table (copy data, source table name: A target table name: B) (access available)Insert into B (a, B, c) Select D, E, F from;
3. Create Table # mytemptable (COLA int primary key)Insert into # mytemptable values (1)
4. Se
) statistical functions of data records:
AVG (field name) returns the average value of a table columnCount (* | field name) statistics on the number of data rows or the number of data rows with values in a columnMax (field name) obtains the maximum value of a table column.Min (field name) obtains the minimum value of a table column.Sum (field name) adds the values in the data column
The method for referencing the above functions:
SQL = "select sum (fi
for a datetime value, you can now request to wait for a T-SQL statement that affects at least one line. You can specify a command to wait for one of the following statements: Select, insert, update, delete, or receive. The first four do not need to be explained; Receive refers to receiving a message from the queue. If you want to stop waiting after a specified number of milliseconds, you can choose to specify a timeout value. The
I saw a post in the Forum a few days ago asking if I could check the SQL Server syntax in the application. I was not clear at the time. Today, I checked SQL Server set settings and found that there are two options to implement this function:
1. Set parseonly option (similar to cntrl + F5 of SSMs)
This option checks the synt
The basic statement of T-SQL, most people are very familiar with, today help house small Editor and everyone to share the SQL statement, T-SQL usage and syntax, as well as some examples, the purpose is to help everyone to review the basic statements of T-SQL, so that the pro
Introduction: SQL Server and Microsoft Access are both Microsoft products. The former is used for medium-sized enterprise applications, and the latter is representative of small databases, which is easy for beginners to master. When developing general information systems, especially the standalone version, most of them use access. Although SQL server also has a personal desktop edition, it consumes a large
Summary of index, foreign key, and field syntax maintenance for mysql, SQL Server, and oracle databases, and SQL Server oracle
Summary of index, foreign key, and field syntax maintenance for mysql, SQL Server, and oracle databases
1. MYSQL database 1) Create an index
Create
The principle of a function to prevent SQL injection is to use regular expressions to match the syntax of SQL injection and add restrictions, which effectively limits SQL injection.
The principle of a function to prevent SQL injection is to use regular expressions to mat
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