qb: update builder advanced assignments

README.md

@@ -15,6 +15,7 @@ hood it uses `sqlx/reflectx` package so `sqlx` models will also work with `gocql
 
 * Builders for `SELECT`, `INSERT`, `UPDATE` `DELETE` and `BATCH`
 * Queries with named parameters (:identifier) support
+* Functions support
 * Binding parameters form struct or map
 * Scanning results into structs and slices
 * Automatic query releasing
@@ -85,38 +86,6 @@ type Person struct {
     t.Log(people)
     // [{Patricia Citizen [patricia.citzen@gocqlx_test.com patricia1.citzen@gocqlx_test.com]} {Igy Citizen [igy.citzen@gocqlx_test.com]} {Ian Citizen [ian.citzen@gocqlx_test.com]}]
 }
-
-// Batch insert two rows in a single query, advanced struct binding.
-{
-    i := qb.Insert("gocqlx_test.person").Columns("first_name", "last_name", "email")
-
-    stmt, names := qb.Batch().
-        AddWithPrefix("a", i).
-        AddWithPrefix("b", i).
-        ToCql()
-
-    batch := struct {
-        A Person
-        B Person
-    }{
-        A: Person{
-            "Igy",
-            "Citizen",
-            []string{"igy.citzen@gocqlx_test.com"},
-        },
-        B: Person{
-            "Ian",
-            "Citizen",
-            []string{"ian.citzen@gocqlx_test.com"},
-        },
-    }
-
-    q := gocqlx.Query(session.Query(stmt), names).BindStruct(&batch)
-
-    if err := q.ExecRelease(); err != nil {
-        t.Fatal(err)
-    }
-}
 ```
 
 See more examples in [example_test.go](https://github.com/scylladb/gocqlx/blob/master/example_test.go).

example_test.go

@@ -89,6 +89,22 @@ func TestExample(t *testing.T) {
 		}
 	}
 
+	// Advanced update, adding and removing elements to collections and counters.
+	{
+		stmt, names := qb.Update("gocqlx_test.person").
+			AddNamed("email", "new_email").
+			Where(qb.Eq("first_name"), qb.Eq("last_name")).
+			ToCql()
+
+		q := gocqlx.Query(session.Query(stmt), names).BindStructMap(p, qb.M{
+			"new_email": []string{"patricia2.citzen@gocqlx_test.com", "patricia3.citzen@gocqlx_test.com"},
+		})
+
+		if err := q.ExecRelease(); err != nil {
+			t.Fatal(err)
+		}
+	}
+
 	// Batch insert two rows in a single query, advanced struct binding.
 	{
 		i := qb.Insert("gocqlx_test.person").Columns("first_name", "last_name", "email")
@@ -137,7 +153,7 @@ func TestExample(t *testing.T) {
 		}
 
 		t.Log(p)
-		// {Patricia Citizen [patricia.citzen@gocqlx_test.com patricia1.citzen@gocqlx_test.com]}
+		// {Patricia Citizen [patricia.citzen@gocqlx_test.com patricia1.citzen@gocqlx_test.com patricia2.citzen@gocqlx_test.com patricia3.citzen@gocqlx_test.com]}
 	}
 
 	// Select, load all the results into a slice.
@@ -156,7 +172,7 @@ func TestExample(t *testing.T) {
 		}
 
 		t.Log(people)
-		// [{Patricia Citizen [patricia.citzen@gocqlx_test.com patricia1.citzen@gocqlx_test.com]} {Igy Citizen [igy.citzen@gocqlx_test.com]} {Ian Citizen [ian.citzen@gocqlx_test.com]}]
+		// [{Ian Citizen [ian.citzen@gocqlx_test.com]} {Igy Citizen [igy.citzen@gocqlx_test.com]} {Patricia Citizen [patricia.citzen@gocqlx_test.com patricia1.citzen@gocqlx_test.com patricia2.citzen@gocqlx_test.com patricia3.citzen@gocqlx_test.com]}]
 	}
 
 	// Easy token based pagination.
@@ -168,6 +184,7 @@ func TestExample(t *testing.T) {
 		}
 
 		stmt, names := qb.Select("gocqlx_test.person").
+			Columns("first_name").
 			Where(qb.Token("first_name").Gt()).
 			Limit(10).
 			ToCql()
@@ -180,7 +197,7 @@ func TestExample(t *testing.T) {
 		}
 
 		t.Log(people)
-		// [{Patricia Citizen [patricia.citzen@gocqlx_test.com patricia1.citzen@gocqlx_test.com]} {Igy Citizen [igy.citzen@gocqlx_test.com]}]
+		// [{Patricia  []} {Igy  []}]
 	}
 
 	// Named query compilation.

qb/cmp.go

@@ -53,15 +53,15 @@ func (c Cmp) writeCql(cql *bytes.Buffer) (names []string) {
 		cql.WriteString(" CONTAINS ")
 	}
 
-	if c.fn == nil {
+	if c.fn != nil {
+		names = append(names, c.fn.writeCql(cql)...)
+	} else {
 		cql.WriteByte('?')
 		if c.name == "" {
 			names = append(names, c.column)
 		} else {
 			names = append(names, c.name)
 		}
-	} else {
-		names = append(names, c.fn.writeCql(cql)...)
 	}
 
 	return
@@ -188,7 +188,7 @@ func GtOrEqNamed(column, name string) Cmp {
 	}
 }
 
-// GtFunc produces column>=someFunc(?...).
+// GtOrEqFunc produces column>=someFunc(?...).
 func GtOrEqFunc(column string, fn *Func) Cmp {
 	return Cmp{
 		op:     geq,

qb/update.go

@@ -9,16 +9,41 @@ package qb
 
 import (
 	"bytes"
+	"fmt"
 )
 
+// assignment specifies an assignment in a set operation.
+type assignment struct {
+	column string
+	name   string
+	expr   bool
+	fn     *Func
+}
+
+func (a assignment) writeCql(cql *bytes.Buffer) (names []string) {
+	cql.WriteString(a.column)
+	switch {
+	case a.expr:
+		names = append(names, a.name)
+	case a.fn != nil:
+		cql.WriteByte('=')
+		names = append(names, a.fn.writeCql(cql)...)
+	default:
+		cql.WriteByte('=')
+		cql.WriteByte('?')
+		names = append(names, a.name)
+	}
+	return
+}
+
 // UpdateBuilder builds CQL UPDATE statements.
 type UpdateBuilder struct {
-	table   string
+	table       string
-	using   using
+	using       using
-	columns columns
+	assignments []assignment
-	where   where
+	where       where
-	_if     _if
+	_if         _if
-	exists  bool
+	exists      bool
 }
 
 // Update returns a new UpdateBuilder with the given table name.
@@ -39,14 +64,12 @@ func (b *UpdateBuilder) ToCql() (stmt string, names []string) {
 	names = append(names, b.using.writeCql(&cql)...)
 
 	cql.WriteString("SET ")
-	for i, c := range b.columns {
+	for i, a := range b.assignments {
-		cql.WriteString(c)
+		names = append(names, a.writeCql(&cql)...)
-		cql.WriteString("=?")
+		if i < len(b.assignments)-1 {
-		if i < len(b.columns)-1 {
 			cql.WriteByte(',')
 		}
 	}
-	names = append(names, b.columns...)
 	cql.WriteByte(' ')
 
 	names = append(names, b.where.writeCql(&cql)...)
@@ -80,7 +103,51 @@ func (b *UpdateBuilder) TTL() *UpdateBuilder {
 
 // Set adds SET clauses to the query.
 func (b *UpdateBuilder) Set(columns ...string) *UpdateBuilder {
-	b.columns = append(b.columns, columns...)
+	for _, c := range columns {
+		b.assignments = append(b.assignments, assignment{
+			column: c,
+			name:   c,
+		})
+	}
+
+	return b
+}
+
+// SetFunc adds SET column=someFunc(?...) clause to the query.
+func (b *UpdateBuilder) SetFunc(column string, fn *Func) *UpdateBuilder {
+	b.assignments = append(b.assignments, assignment{column: column, fn: fn})
+	return b
+}
+
+// Add adds SET column=column+? clauses to the query.
+func (b *UpdateBuilder) Add(column string) *UpdateBuilder {
+	return b.AddNamed(column, column)
+}
+
+// AddNamed adds SET column=column+? clauses to the query with a custom
+// parameter name.
+func (b *UpdateBuilder) AddNamed(column, name string) *UpdateBuilder {
+	b.assignments = append(b.assignments, assignment{
+		column: fmt.Sprint(column, "=", column, "+?"),
+		name:   name,
+		expr:   true,
+	})
+	return b
+}
+
+// Remove adds SET column=column-? clauses to the query.
+func (b *UpdateBuilder) Remove(column string) *UpdateBuilder {
+	return b.RemoveNamed(column, column)
+}
+
+// RemoveNamed adds SET column=column-? clauses to the query with a custom
+// parameter name.
+func (b *UpdateBuilder) RemoveNamed(column, name string) *UpdateBuilder {
+	b.assignments = append(b.assignments, assignment{
+		column: fmt.Sprint(column, "=", column, "-?"),
+		name:   name,
+		expr:   true,
+	})
 	return b
 }
 

qb/update_test.go

@@ -36,6 +36,36 @@ func TestUpdateBuilder(t *testing.T) {
 			S: "UPDATE cycling.cyclist_name SET id=?,user_uuid=?,firstname=?,stars=? WHERE id=? ",
 			N: []string{"id", "user_uuid", "firstname", "stars", "expr"},
 		},
+		// Add SET SetFunc
+		{
+			B: Update("cycling.cyclist_name").SetFunc("user_uuid", Fn("someFunc", "param_0", "param_1")).Where(w).Set("stars"),
+			S: "UPDATE cycling.cyclist_name SET user_uuid=someFunc(?,?),stars=? WHERE id=? ",
+			N: []string{"param_0", "param_1", "stars", "expr"},
+		},
+		// Add SET Add
+		{
+			B: Update("cycling.cyclist_name").Add("total").Where(w),
+			S: "UPDATE cycling.cyclist_name SET total=total+? WHERE id=? ",
+			N: []string{"total", "expr"},
+		},
+		// Add SET AddNamed
+		{
+			B: Update("cycling.cyclist_name").AddNamed("total", "inc").Where(w),
+			S: "UPDATE cycling.cyclist_name SET total=total+? WHERE id=? ",
+			N: []string{"inc", "expr"},
+		},
+		// Add SET Remove
+		{
+			B: Update("cycling.cyclist_name").Remove("total").Where(w),
+			S: "UPDATE cycling.cyclist_name SET total=total-? WHERE id=? ",
+			N: []string{"total", "expr"},
+		},
+		// Add SET RemoveNamed
+		{
+			B: Update("cycling.cyclist_name").RemoveNamed("total", "dec").Where(w),
+			S: "UPDATE cycling.cyclist_name SET total=total-? WHERE id=? ",
+			N: []string{"dec", "expr"},
+		},
 		// Add WHERE
 		{
 			B: Update("cycling.cyclist_name").Set("id", "user_uuid", "firstname").Where(w, Gt("firstname")),