xb

All Filtering Mechanisms (English)

This document is the English counterpart of xb/doc/ALL_FILTERING_MECHANISMS.md. It explains how xb automatically skips empty inputs, how InRequired protects destructive operations, and how higher level blocks behave when their internal conditions collapse.

1. Single-value guards

Eq, Ne, Gt, Gte, Lt, Lte, Like, LikeLeft
Empty strings, zero numbers, false booleans, and nil pointers are ignored.
time.Time values are always serialized (converted to YYYY-MM-DD HH:MM:SS).

xb.Of("t_user").
    Eq("status", 0).      // skipped
    Eq("status", 1).      // included
    Like("name", "").     // skipped
    Like("name", "ai").   // included
    Build()

2. `IN` / `NOT IN`

Entire clauses are removed if every argument is zero, empty, or nil.
Mixed lists are cleaned before rendering.
InRequired panics when the remaining list is empty, which is perfect for admin bulk actions.

xb.Of("orders").
    In("id", 0, nil, 9, 10).         // renders IN (9,10)

xb.Of("orders").
    InRequired("id", ids...).        // panic if ids collapses to empty

3. Compound blocks

Or(func(*CondBuilder)), And(func(*CondBuilder)), Cond(func(*CondBuilder))
If the nested builder produces zero effective conditions, the entire block is dropped, preventing WHERE ().

4. LIKE helpers

Like, NotLike, LikeLeft all skip empty strings.
doLike injects the proper wildcard placement (%foo%, foo%).

5. Debugging tips

Symptom	Explanation
Condition missing	Value was auto-filtered; inspect `built.Conds`
IN disappeared	Input collapsed to zero elements
OR block missing	Every nested condition skipped
Need strict enforcement	Swap to `InRequired` or add `X()` raw expressions

Use fmt.Printf("%#v\n", built.Conds) in tests to inspect the final AST.

doc/en/FILTERING.md – condensed overview
xb/doc/EMPTY_OR_AND_FILTERING.md – legacy Chinese reference
doc/en/TESTING_STRATEGY.md – ideas for asserting automatic filtering in tests

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