What is the design of sql rule engine?
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Recently, I used the rule engine to make a simple summary. The rule, to put it bluntly, is, what is the status quo (fact), if (condition), then (action). The rule engine uses the rete algorithm, and I use drools here. In short, I wrap around a core to generate drl files, and the rest are executed by drools.
In order to facilitate the design, the business is uniformly encapsulated with OP (input parameter: param, entity: body, output parameter: res) and executor Exector, so that class can be introduced less. A label table, a rule engine table. There are all kinds of data, variables, instance variables, relational operations, instructions in the tag.
Conditional direct generation
Behavior
Sql padding: give sql to the rules engine. Sql can take parameters, using parameters from the variable library.
$op.setBody
{
"$op.setBody": "select lock_on_active from t_rule_engine where id='$ {id}'"
}
Query array: query sql to get an array.
Executor.sqlList ($op)
{"Executor.sqlList ($op);": "}
Query value: query sql to get the number
Executor.sqlLong ($op)
{"Executor. SqlLong ($op);": "}
Query map: query sql to get map
Executor.sqlMap ($op)
{"Executor. SqlMap ($op);": "}
Query character: query sql to get a string.
Executor.sqlStr ($op)
{"Executor. SqlStr ($op);": "}
Trigger rules: re-execute in the rules file.
Update ($op)
{"update ($op);": "}
Variable copy: put the result of execution into the reference condition.
Executor.paramCopy
{"Executor.paramCopy": ["data", "data1"]} / / assign the value of the query result data to the parameter data1
Variable assignment: assign a constant value to a variable, which can also be a value in the instance variable library.
Executor.let
{"Executor.let": ["data", "cheitemContent"]} / / assign data to cheitemContent in the reference
At present, only "sql fill" and "variable copy" are parameters, and the others are non-parameter actions.
Finally generate the rule file drl
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