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常用Sqlmysql：drop table if exists tablename;不能写成drop table tablename if exists tablename;mysql：建立索引SqlCREATE TABLE t...mysql：drop table if exists tablename;
不能写成
drop table tablename if exists tablename;
mysql：建立索引Sql
CREATE TABLE tablename (
`ID...
PostgreSQL: insert from another table
I'm trying to insert data to a table from another table and the tables have only one column in common. The problem is, that the TABLE1 has columns that won't accept null values so I can't leave them empty and I can't get them from the TABLE2.
...
How to select only 1 row from oracle sql?
I want to use oracle syntax to select only 1 row from table DUAL . For example, I want to execute this query:
13 Answers
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Nullable Foreign Key bad practice?
Let's say you have a table Orders with a foreign key to a Customer Id. Now, suppose you want to add an Order without a Customer Id, (whether that should be possible is another question) you would have to make the foreign key NULL... Is that bad practice or would you rather work with a link table bet...
Which rows are returned when using LIMIT with OFFSET in MySQL?
...
OFFSET is nothing but a keyword to indicate starting cursor in table
SELECT column FROM table LIMIT 18 OFFSET 8 -- fetch 18 records, begin with record 9 (OFFSET 8)
you would get the same result form
SELECT column FROM table LIMIT 8, 18
visual representation (R is one record in the ...
How can I use an array of function pointers?
...in some derived class.
Often you see something like this
struct function_table {
char *name;
void (*some_fun)(int arg1, double arg2);
};
void function1(int arg1, double arg2)....
struct function_table my_table [] = {
{"function1", function1},
...
So you can reach into the table by ...
How do I reset a sequence in Oracle?
...e to call the thing resetting the sequence back to the max ID used in some table. I end up calling this proc from another script which executes multiple calls for a whole bunch of sequences, resetting nextval back down to some level which is high enough to not cause primary key violations where I'm...
How to perform a real time search and filter on a HTML table
...
I created these examples.
Simple indexOf search
var $rows = $('#table tr');
$('#search').keyup(function() {
var val = $.trim($(this).val()).replace(/ +/g, ' ').toLowerCase();
$rows.show().filter(function() {
var text = $(this).text().replace(/\s+/g, ' ').toLowerCase();
...
jQuery: How can i create a simple overlay?
...imple javascript only solution
function displayOverlay(text) {
$("<table id='overlay'><tbody><tr><td>" + text + "</td></tr></tbody></table>").css({
"position": "fixed",
"top": 0,
"left": 0,
"width": "100%",
...
LINQ to SQL: Multiple joins ON multiple Columns. Is this possible?
...olumns in Linq to SQL is a little different.
var query =
from t1 in myTABLE1List // List<TABLE_1>
join t2 in myTABLE1List
on new { t1.ColumnA, t1.ColumnB } equals new { t2.ColumnA, t2.ColumnB }
...
You have to take advantage of anonymous types and compose a type for the mu...