constraints

How can I use 'Check' statement to validate field value in mysql? look at this page , in the manual didn't discussed about check keyword In MySql Workbench and Navicat for mysql , there is not exists any options to set constraints or check. MySQL does not enforce CHECK constraints. It parses the check constraint clause, but silently ignores it. You'd have to use a trigger to validate data. 来源： https://stackoverflow.com/questions/5131971/how-can-i-use-check-statement-to-validate-field-value-in-mysql

completed: React.PropTypes.number, Can i specify a minimum and maximum to a number props in React component. expected something like following: completed: React.PropTypes.numberBetween(min, max), I generate an array to specify the range attempt: completed: React.PropTypes.oneOf(Array.from({length: max -min+1, (v, k) => k + min})), However , i want completed props to accept also float as well , whereas , it accepts only integer now . How to make the following constraints combined : prop is number ( integer, float, double,...any number) between MIN and MAX You can use Custom Validation.

Could anyone please let me know if there is a way to programatically determine if a Micorosft SQL Server database table field has a NULL or NOT NULL constraint in place? I need this so that I can deploy a patch that is safe to be re-runnable. So I'm after something like this (conceptual/pseudo-code): IF (my_table COLUMN end_date HAS CONSTRAINT OF 'NOT NULL') ALTER TABLE my_table ALTER COLUMN end_date DATETIME NULL So I want to change my_table.end_date from 'NOT NULL' to 'NULL' if it hasn't already been changed. I'm just unsure of what the part in the brackets should be. I know how to

I have a UIScrollView which I'm using to represent an axis on a graph. I'd like the user to be able to zoom in on the axis using the usual pinch motion, but for it to only scale in the vertical direction, not horizontally. My question is similar to this one , but I've tried the solution suggested there (overriding the subview's SetTransform method so that it ignores scaling in one direction) and it works perfectly when constraining scaling horizontally, but not vertically. When I try implementing it vertically the first pinch action works fine, but subsequent pinches seem to reset the zoom

I am currently running multiple linear regression on a dataset. At first, I didn't realize I needed to put constraints over my weights; as a matter of fact, I need to have specific positive & negative weights. To be more precise, I am doing a scoring system and this is why some of my variables should have a positive or negative impact on the note. Yet, when running my model, the results do not fit what I am expecting, some of my 'positive' variables get negative coefficients and vice versa. As an example, let's suppose my model is : y = W0*x0 + W1*x1 + W2*x2 Where x2 is a 'positive' variable,

I have following situation. A main table and many other tables linked together with foreign keys. Now when I would like to delete a row in the main table a ConstraintsViolation will occur, which is intended and good. Now I want to be able to check if the ConstraintsViolation will occur before I trigger the delete row event. Is this possible? If Exists ( Select * From OtherTable Where OtherTableFKColumn = MainTablePrimaryKey) Begin Rollback Transaction RaisError('Violating FK Constraint in Table [OtherTable]', 16, 1) End Other than checking the COUNT(*) of every related table? I don't think so.

I ' am copying data from table A to table B. Table B has a nullable column that has a default constraint value of 0. In general I set values of columns using the following accessor. public object this[string columnName] { get { return DataTable.Rows[CurrentRow][columnName]; } set { DataTable.Rows[CurrentRow][columnName] = value; } } But I do NOT set my nullable column X. When I insert the whole row, the default value is not used. Instead of 0, NULL was inserted for the nullable column. _sqlCommandBuilder = new SqlCommandBuilder(_sqlDataAdapter); _sqlCommandBuilder.ConflictOption =