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Object Query Language (OQL) Syntax
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This feature is not available in NCache Express and Professional edition.
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NCache supports SQL-like language called Object Query Language (OQL). A rich set of operators are provided by NCache according to required query criteria to fetch the desired result set from cache.
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OQL is not case sensitive.
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The following operator categories are supported in NCache queries:
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Category
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Operator
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<Query>
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= , == , != , <> , < , > , <=, >=, IN, LIKE , NOT LIKE
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Logical Operators
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AND , OR , NOT
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Aggregate Functions
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Sum, Count, AVG, Min, Max
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Miscellaneous
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DateTime.Now , DateTime ("any date time compatible string")
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Syntax of the language is explained with the help of examples below:
Basic Query Operators
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Operator
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Description
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Example
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= OR ==
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Equals to
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"SELECT Product WHERE this.ProductID == ?"
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!= OR <>
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Not equals to
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"SELECT Product WHERE this.ProductID <> ?"
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<
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Less than
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"SELECT Product WHERE this.ProductID < ?"
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>
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Greater than
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"SELECT Product WHERE this.ProductID > ?"
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<=
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Less than equal to
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"SELECT Product WHERE this.ProductID <= ?"
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>=
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Greater than equal to
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"SELECT Product WHERE this.ProductID >= ?"
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IN
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In a range
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"SELECT Product this.UnitsAvailable IN (?,?,?,?))"
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LIKE
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Pattern like.
Mostly used for wild card base searching.
Use "*" for one or many occurrence of character.
Use "." for single occurrence of character.
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"SELECT Product WHERE this.ProductName LIKE ? AND this.Category LIKE ?"
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NOT LIKE
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Not like pattern
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"SELECT Product WHERE this.ProductID NOT LIKE ?"
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Logical Query Operators
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Operator
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Description
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Example
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AND
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Retrieve merged result set for two or more conditions.
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"SELECT Product WHERE this.ProductName LIKE ? AND this.Category LIKE ?"
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OR
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Retrieve result set whichfulfills any one condition.
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"SELECT Product WHERE this.ProductName NOT LIKE ? OR this.Category NOT LIKE ?";
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NOT
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Retrieve result set which doesn't match the given criteria.
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"SELECT Product WHERE this.ProductID NOT LIKE ?"
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Aggregate Function
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Operator
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Description
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Example
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Sum
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Calculate sum of result set of specified criteria.
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"SELECT SUM(Product.UnitsAvailable) WHERE this.ProductID <= 10"
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Count
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Calculates count of the result set for a specified criteria.
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"SELECT count(Product) WHERE this.ProductID < ?"
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Avg
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Calculates average of the result set for specified criteria.
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"SELECT AVG(Product.UnitsAvailable) WHERE this.ProductID < ?"
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Min
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Returns minimum of the result set for specified criteria.
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"SELECT MIN(Product.UnitsAvailable) WHERE this.Category = ?"
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Max
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Returns maximum of the result set for specified criteria.
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"SELECT MAX(Product.UnitsAvailable) WHERE this.Category = ?
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Miscellaneous
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Operator
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Description
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Example
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DateTime.Now
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Retrieve result set with respect to current date time.
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"SELECT Order WHERE this.OrderDate = ?"
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DateTime ("any date time compatible string")
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Retrieve result set with respect to specified date time.
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"SELECT Order WHERE this.OrderDate = ?"
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See Also
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