Add a new field to indicate whether to perform a length comparison

[Arty0628]

• [ yes ] Do only one thing
• [ yes ] Non breaking API changes
• [ yes ] Tested

What did this pull request do?

This PR adds a length function to the JSONArrayQuery feature, enabling the comparison of the length of JSON array fields. Specifically, it adds length - related fields to the JSONArrayExpression struct, a new Length method for setting comparison conditions, and implements the construction logic of length comparison SQL statements for MySQL, SQLite, and PostgreSQL databases in the Build method. This resolves the issue that the original code could not verify the equality of JSON array lengths

User Case Description

In the business scenario, data query and creation operations are required based on conditions involving JSON array - type fields. For example, in the DoGetOrCreateStrategyKey interface, data is queried and created according to the incoming StrategyIds array. The original JSONArrayQuery only supports verifying the containment of array elements and cannot verify whether the array lengths are the same. The newly added length function ensures that during querying, existing data is only returned when both the length and content of the JSON array match. When the lengths are the same but the contents are different, it is treated as new data for creation, meeting more precise business query requirements.

Specific example scenario

You can only verify that it belongs to, not that it is equal to, for example, this interface：

func DoGetOrCreateStrategyKey(ctx context.Context, request GetOrCreateStrategyKeyRequest) (*po.key, error) {
	q := query.Use(db.DB).mydb
	clauses := []gen.Condition{q.Source.Eq(request.GetSource()), q.KeyType.Eq(int32(request.GetKeyType()))}
	var attrs []field.AssignExpr
	switch request.GetKeyType() {
	case factory_delivery.StrategyKeyType_SingleStrategy, factory_delivery.StrategyKeyType_MultiStrategy:
		if len(request.StrategyIds) > 5 {
			logs.CtxWarn(ctx, "too many strategy ids")
		}
		for _, sid := range request.StrategyIds {
			clauses = append(clauses, gen.Cond(datatypes.JSONArrayQuery(q.StrategyIds.ColumnName().String()).Contains(sid))...)
		}
		result, err := json.JsonIns.Marshal(request.StrategyIds)
		if err != nil {
			logs.CtxError(ctx, "[GetOrCreateStrategyKey] marshal failed, err: %v", err)
			return nil, bizerr.NewSystemErr("can not marshal data")
		}
		attrs = append(attrs, q.StrategyIds.Value(string(result)))
	default:
		return nil, bizerr.NewParamErr("invalid strategy_key_type")
	}

	do := q.WithContext(ctx).Where(clauses...)
	if request.GetExtra() != "" {
		attrs = append(attrs, q.Extra.Value(request.GetExtra()))
	}
	model, err := do.FirstOrCreate()
	return model, nil
}

Two requests are passed in separately:

{
    "Source": "TEST",
    "StrategyIds": [
        112141551,
        888888888,
        999999988
    ]
}

{
    "Source": "TEST",
    "StrategyIds": [
        112141551,
        888888888
    ]
}

The second request was supposed to create a new piece of data, but it returned the data created by the first request.

After adding the length attribute, you can compare with one click, which is more convenient

[Arty0628]

Add a new field to indicate whether to perform a length comparison

[jinzhu]

Hi @Arty0628

Can you add some tests for this?

[Arty0628]

你好@Arty0628

您可以添加一些测试吗？

@jinzhu Of course, I have pushed the test code, please check it out

[jinzhu]

please fix those tests, thank you.