Transformer Pipeline Module API Reference (JavaScript)  7.1.1.311110
Persistence Module: Pipeline Functions

Detailed Description

The persistence module if loaded exposes some methods to pipelines to enable control of the persistence of data.

Note
The methods in this package are only available if the persistence module is loaded.

Functions

 persist.query (var table, var query, var args, var row_cb, var ordering, var limit)
 Query the Database for matching values. More...
 
 persist.store (var table, var keys, var data)
 Store a value in the persistence Database. More...
 
 persist.remove (var table, var selector)
 Remove a value in the persistence Database. More...
 
 persist.get (var table, var selector, var row_cb, var ordering, var limit)
 Retrieve a value from the persistence Database. More...
 
 persist.call (var procedure, var args, var output_params_cb)
 Call a stored procedure in the persistence Database. More...
 

Function Documentation

persist.call ( var  procedure,
var  args,
var  output_params_cb 
)

Call a stored procedure in the persistence Database.

Parameters
procedureprocedure to be called
argsordered array of input arguments to be passed to be provided as input parameters to the procedure call
output_params_cbfunction to be called with the returned list of output parameters. The callback functions takes one argument containing a map with all the column-value pairs for the output parameters. Keys are always uppercase.
Return values
-1on error.
Returns
1 on success.

This function calls a stored procedure and returns any output parameters as key-value pairs from the parameter name to its string value. The input arguments provided are added as input parameters to the procedure call in the order they are provided.

Keys in the map passed to the callback are always uppercase for DMBS independence.

Example:

persist.call("MY_PROCEDURE", ["a", "10"], function ( output_params ) {
//do something with entries in map, keys are always uppercase
console.log(output_params["b"]);
});
persist.get ( var  table,
var  selector,
var  row_cb,
var  ordering,
var  limit 
)

Retrieve a value from the persistence Database.

Parameters
tabletable to be queried
selectortable containing all the colums with their keys, e.g. { "firstname": "bob", "lastname": "bar" }
row_cbfunction to be called for every row returned by the query. The callback functions takes one argument containing a map with all the column-value pairs for a row.
orderingoptional map of the form { "age": "ASC", "mark": "DESC" } where "ASC" and "DESC" are the only two allowed values
limitoptional max number of rows to be returned
Return values
-1on error.
Returns
Otherwise the number of rows returned by the query

This function executes a query against a database table and returns the rows returned in the result set. The key-value pairs in selector are built into a where clause where every key-value pair represents column/value combinations in the database table and are used in conjunction. A resulting SQL query for a selector { "a": "10", "b": "20" } would look like select * from table where a = 10 and b = 20

Keys in the map passed to the callback are always uppercase for DMBS independence.

Example:

persist.query("MY_TABLE", { "a":10 }, function ( row ) {
//do something with entries in map, keys are always uppercase
console.log(row["A"]);
});
persist.query ( var  table,
var  query,
var  args,
var  row_cb,
var  ordering,
var  limit 
)

Query the Database for matching values.

Parameters
tabletable to be queried
querysql where clause in the format "a=? or b>?" or null for all rows
argsarray of arguments to be bound to the '?' characters in the query, in the form '[ arg1, arg2, arg3 ];
row_cbfunction to be called for every row return by the query. The callback functions takes one argument containing a map with all the column-value pairs for a row.
orderingoptional map of the form { "age": "ASC", "mark": "DESC" } where "ASC" and "DESC" are the only two allowed values
limitoptional max number of rows to be returned
Returns
the number of matched rows

This function executes a query against a database and calls row_cb for every row returned by the query. If this function is called with a query like "a=? and b<?" and an args list of ["foo", "20"] then the resulting sql query would look like: select * from table where a="foo" and b<20

Keys in the map passed to the callback are always uppercase for DMBS independence.

Example:

persist.query("MY_TABLE", "a=?", [ 10 ], function ( row ) {
//do something with entries in map, keys are always uppercase
console.log(row["A"]);
});
persist.remove ( var  table,
var  selector 
)

Remove a value in the persistence Database.

Parameters
tabletable to delete rows from
selectordictionary of key-value pairs to restrict the rows to be deleted.
Return values
-1on error.
Returns
Otherwise the number of deleted rows.

This function attempts to delete rows where all columns specified as keys in selector match the values in selector. A call to this function with a map like { "firstname": "bob", "lastname": "bar" } would result in a sql query similar to delete from table table where firstname = bob and lastname = bar;

persist.store ( var  table,
var  keys,
var  data 
)

Store a value in the persistence Database.

Parameters
tabletable update or insert should be executed against
keysdictionary containing key-value pairs to be used in the where clause for the update
datadictionary containing key-value pairs that should be put
Return values
-1on error.
Returns
Otherwise the number of stored rows.

This function attempts to update rows where all key-value pairs given in keys match column/value pairs in the database. If this operation results in 0 affected rows, then a merged version of keys and data is inserted into the table. If keys and data share columns then the value of the data map will be taken and the value of keys is ignored.


Generated on Fri Mar 23 2018 18:29:30 for Transformer Pipeline Module API Reference (JavaScript)