added in few field wraping functions

pgm.go

@@ -49,6 +49,31 @@ func (f Field) Avg() Field {
 	return Field("AVG(" + f.String() + ")")
 }
 
+func (f Field) Sum() Field {
+	return Field("SUM(" + f.String() + ")")
+}
+
+func (f Field) Max() Field {
+	return Field("MAX(" + f.String() + ")")
+}
+
+func (f Field) Min() Field {
+	return Field("Min(" + f.String() + ")")
+}
+
+func (f Field) Lower() Field {
+	return Field("LOWER(" + f.String() + ")")
+}
+
+func (f Field) Upper() Field {
+	return Field("UPPER(" + f.String() + ")")
+}
+
+func (f Field) Trim() Field {
+	return Field("TRIM(" + f.String() + ")")
+}
+
+// Eq is equal
 func (f Field) Eq(val any) Conditioner {
 	col := f.String()
 	return &Cond{Field: col, Val: val, op: " = $", len: len(col) + 5}
@@ -70,11 +95,21 @@ func (f Field) Gt(val any) Conditioner {
 	return &Cond{Field: col, Val: val, op: " > $", len: len(col) + 5}
 }
 
+func (f Field) Lt(val any) Conditioner {
+	col := f.String()
+	return &Cond{Field: col, Val: val, op: " < $", len: len(col) + 5}
+}
+
 func (f Field) Gte(val any) Conditioner {
 	col := f.String()
 	return &Cond{Field: col, Val: val, op: " >= $", len: len(col) + 5}
 }
 
+func (f Field) Lte(val any) Conditioner {
+	col := f.String()
+	return &Cond{Field: col, Val: val, op: " <= $", len: len(col) + 5}
+}
+
 func (f Field) Like(val string) Conditioner {
 	col := f.String()
 	return &Cond{Field: col, Val: val, op: " LIKE $", len: len(f.String()) + 5}