README
¶
RSQL for MongoDB-Filter
RSQL is a query language based on FIQL (Feed Item Query Language). It's an URI-friendly syntax and therefore well suited for API's.
The language
Basics
RSQL supports multiple comparison operations. The following table gives an overview and a matrix that shows which literals can be used with the corresponding operators.
| Operator | Description | Oid | Bool | String | Number | Array | Example |
|---|---|---|---|---|---|---|---|
| == | equal | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | _id==$oid(ABCDEF012345) title=="Hello World" |
| != | not-equal | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | status!="pending" |
| =gt= | greater-than | ❌ | ❌ | ❌ | ✔️ | ❌ | probability=gt=0.5 |
| =ge= | greater-than-qual | ❌ | ❌ | ✔️ | ❌ | age=ge=18 |
|
| =lt= | less-than | ❌ | ❌ | ❌ | ✔️ | ❌ | probability=lt=0.5 |
| =le= | less-than-equal | ❌ | ❌ | ❌ | ✔️ | ❌ | high=le=1.60 |
| =sw= | starts with | ❌ | ❌ | ✔️ | ❌ | ❌ | table=sw="DB_" |
| =ew= | ends with | ❌ | ❌ | ✔️ | ❌ | ❌ | file=ew=".jpg" |
| =in= | contains | ❌ | ❌ | ❌ | ❌ | ✔️ | log_level=in=("panic","error","warning") |
| =out= | not-contains | ❌ | ❌ | ❌ | ❌ | ✔️ | grade=out=(1,2) |
NOTE: equal and not equal can also be used to check if array contains an single element.
E.g. document has {roles: ["dev","maintainer","admin"]}, than you can check if has admin role by using roles=="admin".
Multiple comparisons can be combined with composite operators:
| Operator | Description | Example |
|---|---|---|
| ; | Logical AND | gender=="female";age=ge=30 |
| , | Logical OR | level=="senior",level=="expert" |
For more advanced queries, context may be helpful.
They can be used by round brackets e.g. (expression;expression),(expression;expression).
A more accurate example could be a binary XOR (only a or b is 1) (a==0;b==1),(a==1;b==0).
Example
For API
import (
"github.com/StevenCyb/goapiutils/parser/mongo/rsql"
"go.mongodb.org/mongo-driver/mongo/options"
)
func ListHandler(w http.ResponseWriter, r *http.Request) {
queryExpressionString := r.URL.Query().Get("query")
parser := rsql.NewParser(nil)
queryExpression, err := parser.Parse(queryExpressionString)
// ...
coll.Find(r.Context(), queryExpression)
// ...
}
For API with policy
This parser supports two types of policies:
WHITELIST_POLICY-> disallow everything except given fieldsBLACKLIST_POLICY-> allow everything except given fields
import (
"github.com/StevenCyb/goapiutils/mongo/rsql"
"github.com/StevenCyb/goapiutils/parser/tokenizer"
"go.mongodb.org/mongo-driver/mongo/options"
)
// ...
queryExpressionString := r.URL.Query().Get("query")
parser := rsql.NewParser(
// just allow expression with
// "first_name", "last_name" and "age"
tokenizer.NewPolicy(
tokenizer.WHITELIST_POLICY,
"first_name", "last_name", "age",
)
)
queryExpression, err := parser.Parse(queryExpressionString)
// ...
coll.Find(r.Context(), queryExpression)
// ...
Documentation
¶
Index ¶
Constants ¶
const ( SkipType tokenizer.Type = "SKIP" AndCompositeType tokenizer.Type = ";" OrCompositeType tokenizer.Type = "," ContextStartType tokenizer.Type = "(" ContextEndType tokenizer.Type = ")" ValueCompareOperatorType tokenizer.Type = "VALUE_COMPARE_OPERATOR" QuotedStringValueCompareOperatorType tokenizer.Type = "QUOTED_STRING_VALUE_COMPARE_OPERATOR" NumericValueCompareOperatorType tokenizer.Type = "NUMERIC_VALUE_COMPARE_OPERATOR" ArrayCompareOperatorType tokenizer.Type = "ARRAY_COMPARE_OPERATOR" BoolLiteralType tokenizer.Type = "BOOL_LITERAL" QuotedStringLiteralType tokenizer.Type = "QUOTED_STRING_LITERAL" OidLiteralType tokenizer.Type = "OID_LITERAL" FieldNameType tokenizer.Type = "FIELD_NAME" NumberLiteralType tokenizer.Type = "NUMERIC_LITERAL" )
Types that are used in this parser.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Source Files