Expression parsing method towards geospatial database attribute value constraint checking

Expression parsing method towards geospatial database attribute value constraint checking

  • CN 104,794,240 B
  • Filed: 05/08/2015
  • Issued: 06/14/2019
  • Est. Priority Date: 05/08/2015
  • Status: Active Grant
First Claim
Patent Images

1. a kind of expression parsing method towards geospatial database attribute value constraint checking, which is characterized in that including such asLower step:

  • Step 1, defined attribute value the constraint relationship expression formulaThe definition mode of attribute value the constraint relationship expression formula are as follows;

    IF<

    exp1>

    Then<

    exp2>

    Wherein, symbol IF<

    exp1>

    indicates that the expression formula exp1 in bracket is conditional expression, and symbol Then<

    exp2>

    expression includesExpression formula exp2 in number is decision expression formula;

    The calculated result of conditional expression and decision expression formula is only true or false, and is all made of following definition mode;

    Exp=(V, A, M, R, L, F)Wherein, exp indicates the expression formula of definition;

    Whole element sets that (V, A, M, R, L, F) expression exp is included;

    VIt is numerical value or character string for self-defining value;

    A is attribute-name;

    M is arithmetic operator, and arithmetic operator includes adding operator+, subtraction operator-, multiplication operator ×

    , division arithmetic symbol/;

    R is relational operator, and relational operator includes greater than operator>

    , greater than or equal to operator>

    =, less-than operator <

    , be less than or equal to operator≤

    , be equal to operator=, be not equal to operator<

    >



    L is logical operator, and logical operator includes union symbol And or operator Or, inverse symbol Not;

    F is functional operation symbol;

    Wherein, V, A are referred to as operand element, and M, R, L, F are referred to as operator elements;

    Step 2, it decomposes and converting attribute value the constraint relationship expression formulaAccording to the definition mode of attribute value the constraint relationship expression formula, attribute value the constraint relationship expression formula is decomposed into conditional expressionExp1 and decision expression formula exp2, and conditional expression, decision expression formula are respectively converted into a symbol sequence sheet formIt is expressed;

    Step 3, analytical expressionValue, the value of decision expression formula of analytical Calculation conditional expression are distinguished according to symbol sequence list;

    Step 4, judge that attribute value constrainsJudge whether attribute value meets attribute value the constraint relationship expression formula according to the value of conditional expression and the value of decision expression formula;

    Geospatial database attribute value the constraint relationship is existed between a data Table Properties value in geospatial databaseThe relationship that mutually limits of one kind;

    A tables of data in the geospatial database is the collection of a kind of geographical space elementIt closes, a referred to as element collection;

    A record in tables of data indicates a geographical space element, and geographical sky is shown in a data listBetween element an attribute.

View all claims
    ×
    ×

    Thank you for your feedback

    ×
    ×