rn 99052

principle. Here is a representative SQL method.Select Country, max (substr (city, 2) CityFrom(Select Country, sys_connect_by_path (city, ',') CityFrom(Select country, city, country | rn rchild, country | (rn-1) rfatherFrom(Select test. Country, test. City, row_number () over (partition by test. Country order by test. City) Rn from test ))Connect by prior rchild

Use sys_connect_by_path to convert multiple rows into single-row strings. Recently, several projects have the need to convert multiple rows into strings. Now we will write an example for your reference. Create a table and insert data: Create Table t_row_str ( ID number, Col varchar2 (10 )); Insert into t_row_str values (1, 'A '); Insert into t_row_str values (1, 'B '); Insert into t_row_str values (1, 'C '); Insert into t_row_str values (2, 'A '); Insert into t_row_str values (2, 'D '); Insert i

values ('t502', 'x1', 3) Insert into tb1 values ('t503', 'x1', 53)Insert into tb1 values ('t503', 'x1', 44)Insert into tb1 values ('t503', 'x1', 50)Insert into tb1 values ('t503', 'x1', 23) -- Auto-increment is required in sqlserver2000.Alter table tb1 add ID int identityGoDeclare @ s varchar (8000)Set @ s = 'select cpici'Select @ s = @ s + ', max (case when Rn =' + ltrim (RN) + 'then cvalue end) as cvlue

values ('t502', 'x1', 3) Insert into tb1 values ('t503', 'x1', 53)Insert into tb1 values ('t503', 'x1', 44)Insert into tb1 values ('t503', 'x1', 50)Insert into tb1 values ('t503', 'x1', 23) -- Auto-increment is required in sqlserver2000.Alter table tb1 add ID int identityGoDeclare @ s varchar (8000)Set @ s = 'select cpici'Select @ s = @ s + ', max (case when Rn =' + ltrim (RN) + 'then cvalue end) as cvlue

-> get_address ($ this-> strip_comment ($ from ));$ Body = ereg_replace ("(^ | (rn) (.)", "1.3", $ body );$ Header. = "MIME-Version: 1.0rn ";If ($ mailtype = "HTML "){$ Header. = "Content-Type: text/htmlrn ";}$ Header. = "To:". $ to. "rn ";If ($ cc! = ""){$ Header. = "Cc:". $ cc. "rn ";}$ Header. = "From: $ from $ Header. = "Subject:". $ subject. "

want to talk about the differences in checking all the existing variables. the code is as follows: $ A = 100; $ B = ""; $ C = null; // Isset check Echo "isset", "$ a = $ a", isset ($ )? "Define": "undefine", "rn "; Echo "isset", "$ B = $ B", isset ($ B )? "Define": "undefine", "rn "; Echo "isset", "$ c = $ c", isset ($ c )? "Define": "undefine", "

provides many new commands. (1) The clz Rd, RM ---- zero count command is used to calculate the number of zeros between the highest sign bit and the first 1. This command is useful in speech/audio codec normalization operations. For example, using armv4 ISA to implement forward zero count may use several commands. (2) qadd Rd, RM, RN --- RD = SAT (RM + rn) Qdadd Rd, RM,

)Bool (true)Bool (false) Is_null.It can be seen that empty () can be used to determine whether all data types are NULL or false, while is_null is basically the same as isset and can only be used to determine whether it is NULL or undefined.To sum up the differences among isset, empty, and is_null:As described earlier: checking variables and parameter types are the basis for the differences between the three functions and are also the most overlooked. I can see many articles comparing these thre

differences between the three functions and are also the most overlooked. I can see many articles comparing these three functions on the Internet. This is rarely involved. Next I want to talk about the differences in checking all existing variables. The Code is as follows:$ A = 100;$ B = "";$ C = null;// Isset checkEcho "isset", "$ a = $ a", isset ($ )? "Define": "www.111cN.net undefine", "rn ";Echo "isset", "$ B = $ B", isset ($ B )? "Define": "unde

difference between these 3 functions, and is the most easily overlooked. See there are a lot of comparisons on this 3 functions on the web. These are rarely involved. What I'm going to say here is the difference between checking for variables that already exist. The code is as follows Copy Code $a = 100; $b = ""; $c =null; //isset Check echo "Isset", "$a = $a", isset ($a)? " Define ":" Www.111cN.net undefine "," RN "

test values (' Nvwang ', ' Ye '); INSERT into test values (' Happy ', ' Leaf '); Commit 3. Query Sql> select * from test; Dname ename ---------- ---------- Guowang Andy Guowang Zhang Guowang Chong Nvwang Tao Nvwang Ye Happy Leaf 6 rows selected. Target Conversion Mode: Dname NAME ---------- ---------------- Guowang Andy,zhang,chong Nvwang Tao,ye Happy Leaf 4. Conversion Method One: A simple way to pass a function, with Oracle versioning as an alternative. Sql> col name for A40 Sql> Select D

(' T502 ', ' X1 ', 22)INSERT into tb1 values (' T502 ', ' X1 ', 3)INSERT into tb1 values (' T503 ', ' X1 ', 53)INSERT into tb1 values (' T503 ', ' X1 ', 44)INSERT into tb1 values (' T503 ', ' X1 ', 50)INSERT into tb1 values (' T503 ', ' X1 ', 23)--the need for self-enhancement in sqlserver2000ALTER TABLE TB1 add ID int identityGoDECLARE @s varchar (8000)Set @s= ' Select Cpici 'Select @[email protected]+ ', max (case is rn= ' +ltrim (

Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 Conntect by problem SQL: 1. The most common method of connect by is www.2cto.com select SYS_CONNECT_BY_PATH (sal, ',') from (select sal, ROW_NUMBER () over (partition by deptno order by sal) rn, ROW_NUMBER () over (partition by deptno order by sal)-1 as dn from scott. emp where deptno = '20') start with rn = 1 connect by prior

; get_address ($ this-> strip_comment ($ from ));$ Body = ereg_replace ("(^ | (rn) (.)", "1.3", $ body );$ Header. = "MIME-Version: 1.0rn ";If ($ mailtype = "HTML "){$ Header. = "Content-Type: text/html; charsets = utf-8rn ";}$ Header. = "To:". $ to. "rn ";If ($ cc! = ""){$ Header. = "Cc:". $ cc. "rn ";}$ Header. = "From: $ fromname $ Header. = "Subject:". $ subj

involved. Next I want to talk about the differences in checking all existing variables. The code is as follows: $ A = 100;$ B = "";$ C = null;// Isset checkEcho "isset", "$ a = $ a", isset ($ )? "Define": "undefine", "rn ";Echo "isset", "$ B = $ B", isset ($ B )? "Define": "undefine", "rn ";Echo "isset", "$ c = $ c", isset ($ c )? "Define": "undefine", "