sql query to compare two columns in same table

Http://cheneyph.iteye.com/blog/477829 In Java, there are several methods to obtain the total number of rows of the resultset. First, use the getrow method of the resultset to obtain the total number of rows of the resultset. Statement stmt = con. createstatement (resultset. type_scroll_insensitive, resultset. concur_updatable );Resultset rset = stmt.exe cutequery ("select * From yourtablename ");Rset. Last ();Int rowcount = rset. getrow (); // obtain the total number of rows in the resu

Select Top 12 ID, URL, titleorname from t_userscolumn A where Mark = '1' and not exists (select * From t_userscolumn where url =. URL and titleorname =. titleorname and Mark = '1' and ID>. ID) order by ID DESC ========================================================== ======== Remove duplicate values from SQL Server 2000 the table structure is zymc -- major name, NJ -- grade, xnxqh -- academic year nu

Label:Find the maximum value for multiple columns in one row in a SQL Server table Sometimes we need to find the largest value from multiple identical joins (the same data type for these columns) and show Here is an example IF(object_id('tempdb: # #TestTable') is not NULL) DROP

' --true display, false --where birthday> ' 1990-01-01 ' SELECT sex from info WHERE SEX was not NULL SELECT SNAME from info WHERE SNAME like '% Month ' ------back up INFO table to Info--bak --1 Info_bak -- 2 Insert query Data Select *into Intfo_bak from INFO-two functions to create a new table Insert query data

('t0002','u0005',29.8);INSERT into' Test_a ' (' trade_id ', 'user_id', ' Amount ')VALUES('t0003','u0002',3050);INSERT into' Test_a ' (' trade_id ', 'user_id', ' Amount ')VALUES('t0004','u0003',128.4);INSERT into' Test_a ' (' trade_id ', 'user_id', ' Amount ')VALUES('t0005','u0004',33.7);INSERT into' Test_b ' (' trade_id ', 'user_id', ' Amount ')VALUES('t0001','u0001', -);INSERT into' Test_b ' (' trade_id ', 'user_id', ' Amount ')VALUES('t0002','u0005',29.8);INSERT into' Test_b ' (' trade_i

Tags: style blog http color io ar for strong SPSQL query table, all field names of the table2011-07-29 10:21:43|Category: SQL Server | Tags: table sql fields | Report | Font size Subscription SQL

-- Add columns in the table cyclicallySet nocount on Declare @ barcode_head varchar (10)Declare @ SQL varchar (500) -- Declare a cursorDeclare business_cursor cursorSelect barcode_head from s_business order by ID Open business_cursorFetch next from business_cursor into @ barcode_head While @ fetch_status = 0BeginPrint @ barcode_headSet @

Label:The columns of table two are updated to table one (same library, cross-Library), and the A and B tables are associated by field Empid. Requires that updates between the associated records need to be one by one corresponding to the relationship. The statements are as follows:Update Set = from where = Table Two. E

Label:You can add a new column to a table by using the ALTER keyword. Like what: Add a column to the table for persons with the name birthday, and the type is date. ALTER TABLE Persons ADD Birthday Date The format for using ALTER is: ALTER TABLE table_name ADD column_name datatype The action to delete a column in a

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 1 Method 2: Select Top 0 * Into B From A 2Description: Copy table (copy data, source

: This article mainly introduces the SQL statement for the same table. PHP queries the sum of two columns of data and then outputs the results. if you are interested in the PHP Tutorial, you can refer to it. // Calculate the total order quantity $query_num = "SELECT SUM(order_num) from hcf_order_db where order_id = XXX";$arr_qn = mysqli_query($dbc,$query_num);li

You can't add that!Some data is null, null+ any value =nullNot if you say that.Update Set HY_MYGGCYSWCQKB. Sj_by_sr=hy_myggcyswcqkb. Sj_by_sr+hy_myggcyswcqkb. Sj_by_sr_tz-hy_myggcyswcqkb. SJ_BY_SR_TJ;If there is a column that is not NULL, the result of the addition is null.Normal, yes.SELECT Total + Money From TableYou can do it.But:Some of the data is empty and needs to be based on different databases, with unused functionsThat is, if the data is empty, then it is calculated according to

There are associations between multiple tables in the actual project. It is impossible to retrieve all data in a table. If there is no table connection, we need a lot of operations. For example, you need to find restrictive conditions from Table A to retrieve data from Table B. It is not only necessary to split multipl

The actual project, there are multiple tables of the association relationship. It is impossible to retrieve all the data in a single table. If there is no table connection, then we need a lot of action. For example, you need to find restrictive conditions from table A to retrieve data from table B. Not only need to be

Here are two tables, they have exactly the same structure, please find the columns with different values through SQL. Student_1 NAME Age SCORE Peter 26 100 Jack 25 96 Daniel 26 48 Bark 21st 69 Student_2 NAME Age SCORE Peter 26 89 Jack 25

The original table is in the following format: Class calldate Callcount 1 2005-8-8 40 1 2005-8-7 6 2 2005-8-8 77 3 2005-8-9 33 3 2005-8-8 9 3 2005-8-7 21 According to the value of class, the Callcount1,callcount2,callcount3 are counted by date respectively. When the date has no record value of 0 Requirements are merged into the following format: Calldate CallCount1 CallCount2 CallCount3 2005-8-9 0 0 33 2005-8-8 40 77 9 2005-8-7 6 0 21 --Create a test

replacement string substring replace Copy Code code as follows: --Example 1: Update Tbpersonalinfo Set truename = replace (truename,substring (truename,2,4), ' * * ') where ID = 1 --Example 2: Update Tbpersonalinfo Set Mobile = replace (mobile,substring (mobile,4,11), ' ******** ') where ID = 1 --Example 3: Update Tbpersonalinfo Set Email = replace (email, ' chinamobile ', ' Hu Jintao ') Where ID = 1 SQL

SQL statement join Table query and SQL statement join query Answers to questions about SQL statement join Table query 1. Create two databa

SQL alert commands are used to modify data table names, add columns, delete columns, modify field data types, and so on. All right, let's take a look at the example below. Database ALTER TABLE syntaxTo add a column to a table,