diff --git a/cel2sql.go b/cel2sql.go
index fe40528..4f90bcd 100644
--- a/cel2sql.go
+++ b/cel2sql.go
@@ -37,7 +37,6 @@ func (con *converter) visit(expr *exprpb.Expr) error {
 	switch expr.ExprKind.(type) {
 	case *exprpb.Expr_CallExpr:
 		return con.visitCall(expr)
-	// TODO: Comprehensions are currently not supported.
 	case *exprpb.Expr_ComprehensionExpr:
 		return con.visitComprehension(expr)
 	case *exprpb.Expr_ConstExpr:
@@ -279,9 +278,74 @@ func (con *converter) visitCallUnary(expr *exprpb.Expr) error {
 }
 
 func (con *converter) visitComprehension(expr *exprpb.Expr) error {
-	// TODO: introduce a macro expansion map between the top-level comprehension id and the
-	// function call that the macro replaces.
-	return fmt.Errorf("unimplemented : %v", expr)
+	c := expr.GetComprehensionExpr()
+
+	loopStep := c.GetLoopStep().GetCallExpr()
+	if loopStep == nil {
+		return fmt.Errorf("unsupported macro")
+	}
+	loopFunction := loopStep.GetFunction()
+	loopArgs := loopStep.GetArgs()
+
+	con.str.WriteString("SELECT ")
+	switch loopFunction {
+	case operators.LogicalAnd:
+		con.str.WriteString("COUNT(*) = 0")
+	case operators.LogicalOr:
+		con.str.WriteString("COUNT(*) > 0")
+	case operators.Add:
+		// map
+		con.str.WriteString("ARRAY_AGG(")
+		if err := con.visit(loopArgs[1].GetListExpr().GetElements()[0]); err != nil {
+			return err
+		}
+		con.str.WriteString(")")
+	case operators.Conditional:
+		switch loopArgs[1].GetCallExpr().GetArgs()[1].ExprKind.(type) {
+		case *exprpb.Expr_ConstExpr:
+			// exists_one
+			con.str.WriteString("COUNT(*) = 1")
+		case *exprpb.Expr_ListExpr:
+			// filter
+			con.str.WriteString("ARRAY_AGG(")
+			if err := con.visit(loopArgs[1].GetCallExpr().GetArgs()[1].GetListExpr().GetElements()[0]); err != nil {
+				return err
+			}
+			con.str.WriteString(")")
+		default:
+			return fmt.Errorf("unsupported macro")
+		}
+	default:
+		return fmt.Errorf("unsupported macro")
+	}
+	con.str.WriteString(" FROM UNNEST(")
+	if err := con.visit(c.GetIterRange()); err != nil {
+		return err
+	}
+	con.str.WriteString(") AS `")
+	con.str.WriteString(c.GetIterVar())
+	con.str.WriteString("`")
+	switch loopFunction {
+	case operators.LogicalAnd, operators.LogicalOr, operators.Conditional:
+		con.str.WriteString(" WHERE ")
+	}
+	switch loopFunction {
+	case operators.LogicalAnd:
+		con.str.WriteString("NOT (")
+		if err := con.visit(loopArgs[1]); err != nil {
+			return err
+		}
+		con.str.WriteString(")")
+	case operators.LogicalOr:
+		if err := con.visit(loopArgs[1]); err != nil {
+			return err
+		}
+	case operators.Conditional:
+		if err := con.visit(loopArgs[0]); err != nil {
+			return err
+		}
+	}
+	return nil
 }
 
 func (con *converter) visitConst(expr *exprpb.Expr) error {
diff --git a/cel2sql_test.go b/cel2sql_test.go
index 66bc310..7197535 100644
--- a/cel2sql_test.go
+++ b/cel2sql_test.go
@@ -252,6 +252,36 @@ func TestConvert(t *testing.T) {
 			want:    "\"test\" IN UNNEST(`trigram`.`cell`[OFFSET(0)].`value`)",
 			wantErr: false,
 		},
+		{
+			name:    "macro_all",
+			args:    args{source: `trigram.cell.all(cell, cell.page_count > 0)`},
+			want:    "SELECT COUNT(*) = 0 FROM UNNEST(`trigram`.`cell`) AS `cell` WHERE NOT (`cell`.`page_count` > 0)",
+			wantErr: false,
+		},
+		{
+			name:    "macro_exists",
+			args:    args{source: `trigram.cell.exists(cell, cell.page_count > 0)`},
+			want:    "SELECT COUNT(*) > 0 FROM UNNEST(`trigram`.`cell`) AS `cell` WHERE `cell`.`page_count` > 0",
+			wantErr: false,
+		},
+		{
+			name:    "macro_exists_one",
+			args:    args{source: `trigram.cell.exists_one(cell, cell.page_count > 0)`},
+			want:    "SELECT COUNT(*) = 1 FROM UNNEST(`trigram`.`cell`) AS `cell` WHERE `cell`.`page_count` > 0",
+			wantErr: false,
+		},
+		{
+			name:    "macro_filter",
+			args:    args{source: `trigram.cell.filter(cell, cell.page_count > 0)`},
+			want:    "SELECT ARRAY_AGG(`cell`) FROM UNNEST(`trigram`.`cell`) AS `cell` WHERE `cell`.`page_count` > 0",
+			wantErr: false,
+		},
+		{
+			name:    "macro_map",
+			args:    args{source: `trigram.cell.map(cell, cell.page_count + 1)`},
+			want:    "SELECT ARRAY_AGG(`cell`.`page_count` + 1) FROM UNNEST(`trigram`.`cell`) AS `cell`",
+			wantErr: false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {