treewide: get rid of (most) uses of QueryResult::rows

This commit serves two purposes:

- Modernizes the existing examples and internal uses of QueryResult in
  the driver. We have had helpers such as rows_typed etc. for a long
  time and they are supposed to offer superior experience, although many
  of our tests still use QueryResult::rows directly.
- Prepares for the iterator-based deserialization refactor. The
  representation of QueryResult will change and the rows field will not
  be available anymore - instead, the helper methods very similar to the
  current ones will be mandatory.

Co-authored-by: Wojciech Przytuła <[email protected]>

README.md

@@ -19,11 +19,10 @@ let uri = "127.0.0.1:9042";
 
 let session: Session = SessionBuilder::new().known_node(uri).build().await?;
 
-if let Some(rows) = session.query("SELECT a, b, c FROM ks.t", &[]).await?.rows {
-    for row in rows.into_typed::<(i32, i32, String)>() {
-        let (a, b, c) = row?;
-        println!("a, b, c: {}, {}, {}", a, b, c);
-    }
+let result = session.query("SELECT a, b, c FROM ks.t", &[]).await?;
+let mut iter = result.rows_typed::<(i32, i32, String)>()?;
+while let Some((a, b, c)) = iter.next().transpose()? {
+    println!("a, b, c: {}, {}, {}", a, b, c);
 }
 ```
 

docs/source/data-types/blob.md

@@ -17,10 +17,10 @@ session
     .await?;
 
 // Read blobs from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(Vec<u8>,)>() {
-        let (blob_value,): (Vec<u8>,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(Vec<u8>,)>()?;
+while let Some((blob_value,)) = iter.next().transpose()? {
+    println!("{:?}", blob_value);
 }
 # Ok(())
 # }

docs/source/data-types/collections.md

@@ -17,10 +17,10 @@ session
     .await?;
 
 // Read a list of ints from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(Vec<i32>,)>() {
-        let (list_value,): (Vec<i32>,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(Vec<i32>,)>()?;
+while let Some((list_value,)) = iter.next().transpose()? {
+    println!("{:?}", list_value);
 }
 # Ok(())
 # }
@@ -43,10 +43,10 @@ session
     .await?;
 
 // Read a set of ints from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(Vec<i32>,)>() {
-        let (set_value,): (Vec<i32>,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(Vec<i32>,)>()?;
+while let Some((list_value,)) = iter.next().transpose()? {
+    println!("{:?}", list_value);
 }
 # Ok(())
 # }
@@ -67,10 +67,10 @@ session
     .await?;
 
 // Read a set of ints from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(HashSet<i32>,)>() {
-        let (set_value,): (HashSet<i32>,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(HashSet<i32>,)>()?;
+while let Some((list_value,)) = iter.next().transpose()? {
+    println!("{:?}", list_value);
 }
 # Ok(())
 # }
@@ -91,10 +91,10 @@ session
     .await?;
 
 // Read a set of ints from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(BTreeSet<i32>,)>() {
-        let (set_value,): (BTreeSet<i32>,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(BTreeSet<i32>,)>()?;
+while let Some((list_value,)) = iter.next().transpose()? {
+    println!("{:?}", list_value);
 }
 # Ok(())
 # }
@@ -120,10 +120,10 @@ session
     .await?;
 
 // Read a map from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(HashMap<String, i32>,)>() {
-        let (map_value,): (HashMap<String, i32>,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(HashMap<String, i32>,)>()?;
+while let Some((map_value,)) = iter.next().transpose()? {
+    println!("{:?}", map_value);
 }
 # Ok(())
 # }
@@ -146,10 +146,10 @@ session
     .await?;
 
 // Read a map from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(BTreeMap<String, i32>,)>() {
-        let (map_value,): (BTreeMap<String, i32>,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(BTreeMap<String, i32>,)>()?;
+while let Some((map_value,)) = iter.next().transpose()? {
+    println!("{:?}", map_value);
 }
 # Ok(())
 # }

docs/source/data-types/counter.md

@@ -11,11 +11,11 @@ use scylla::IntoTypedRows;
 use scylla::frame::value::Counter;
 
 // Read counter from the table
-if let Some(rows) = session.query("SELECT c FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(Counter,)>() {
-        let (counter_value,): (Counter,) = row?;
-        let counter_int_value: i64 = counter_value.0;
-    }
+let result = session.query("SELECT c FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(Counter,)>()?;
+while let Some((counter_value,)) = iter.next().transpose()? {
+    let counter_int_value: i64 = counter_value.0;
+    println!("{}", counter_int_value);
 }
 # Ok(())
 # }

docs/source/data-types/date.md

@@ -67,14 +67,10 @@ session
     .await?;
 
 // Read NaiveDate from the table
-if let Some(rows) = session
-    .query("SELECT a FROM keyspace.table", &[])
-    .await?
-    .rows
-{
-    for row in rows.into_typed::<(NaiveDate,)>() {
-        let (date_value,): (NaiveDate,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(NaiveDate,)>()?;
+while let Some((date_value,)) = iter.next().transpose()? {
+    println!("{:?}", date_value);
 }
 # Ok(())
 # }
@@ -105,14 +101,10 @@ session
     .await?;
 
 // Read Date from the table
-if let Some(rows) = session
-    .query("SELECT a FROM keyspace.table", &[])
-    .await?
-    .rows
-{
-    for row in rows.into_typed::<(Date,)>() {
-        let (date_value,): (Date,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(Date,)>()?;
+while let Some((date_value,)) = iter.next().transpose()? {
+    println!("{:?}", date_value);
 }
 # Ok(())
 # }

docs/source/data-types/decimal.md

@@ -52,10 +52,10 @@ session
     .await?;
 
 // Read a decimal from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(BigDecimal,)>() {
-        let (decimal_value,): (BigDecimal,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(BigDecimal,)>()?;
+while let Some((decimal_value,)) = iter.next().transpose()? {
+    println!("{:?}", decimal_value);
 }
 # Ok(())
 # }

docs/source/data-types/duration.md

@@ -9,17 +9,17 @@
 use scylla::IntoTypedRows;
 use scylla::frame::value::CqlDuration;
 
-// Insert some ip address into the table
+// Insert some duration into the table
 let to_insert: CqlDuration = CqlDuration { months: 1, days: 2, nanoseconds: 3 };
 session
     .query("INSERT INTO keyspace.table (a) VALUES(?)", (to_insert,))
     .await?;
 
-// Read inet from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(CqlDuration,)>() {
-        let (cql_duration,): (CqlDuration,) = row?;
-    }
+// Read duration from the table
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(CqlDuration,)>()?;
+while let Some((duration_value,)) = iter.next().transpose()? {
+    println!("{:?}", duration_value);
 }
 # Ok(())
 # }

docs/source/data-types/inet.md

@@ -16,10 +16,10 @@ session
     .await?;
 
 // Read inet from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(IpAddr,)>() {
-        let (inet_value,): (IpAddr,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(IpAddr,)>()?;
+while let Some((inet_value,)) = iter.next().transpose()? {
+    println!("{:?}", inet_value);
 }
 # Ok(())
 # }

docs/source/data-types/primitive.md

@@ -1,6 +1,7 @@
 # Bool, Tinyint, Smallint, Int, Bigint, Float, Double
 
 ### Bool
+
 `Bool` is represented as rust `bool`
 
 ```rust
@@ -17,16 +18,17 @@ session
     .await?;
 
 // Read a bool from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(bool,)>() {
-        let (bool_value,): (bool,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(bool,)>()?;
+while let Some((bool_value,)) = iter.next().transpose()? {
+    println!("{}", bool_value);
 }
 # Ok(())
 # }
 ```
 
 ### Tinyint
+
 `Tinyint` is represented as rust `i8`
 
 ```rust
@@ -43,16 +45,17 @@ session
     .await?;
 
 // Read a tinyint from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(i8,)>() {
-        let (tinyint_value,): (i8,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(i8,)>()?;
+while let Some((tinyint_value,)) = iter.next().transpose()? {
+    println!("{:?}", tinyint_value);
 }
 # Ok(())
 # }
 ```
 
 ### Smallint
+
 `Smallint` is represented as rust `i16`
 
 ```rust
@@ -69,16 +72,17 @@ session
     .await?;
 
 // Read a smallint from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(i16,)>() {
-        let (smallint_value,): (i16,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(i16,)>()?;
+while let Some((smallint_value,)) = iter.next().transpose()? {
+    println!("{}", smallint_value);
 }
 # Ok(())
 # }
 ```
 
 ### Int
+
 `Int` is represented as rust `i32`
 
 ```rust
@@ -95,16 +99,17 @@ session
     .await?;
 
 // Read an int from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(i32,)>() {
-        let (int_value,): (i32,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(i32,)>()?;
+while let Some((int_value,)) = iter.next().transpose()? {
+    println!("{}", int_value);
 }
 # Ok(())
 # }
 ```
 
 ### Bigint
+
 `Bigint` is represented as rust `i64`
 
 ```rust
@@ -121,16 +126,17 @@ session
     .await?;
 
 // Read a bigint from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(i64,)>() {
-        let (bigint_value,): (i64,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(i64,)>()?;
+while let Some((bigint_value,)) = iter.next().transpose()? {
+    println!("{:?}", bigint_value);
 }
 # Ok(())
 # }
 ```
 
-### Float 
+### Float
+
 `Float` is represented as rust `f32`
 
 ```rust
@@ -147,16 +153,17 @@ session
     .await?;
 
 // Read a float from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(f32,)>() {
-        let (float_value,): (f32,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(f32,)>()?;
+while let Some((float_value,)) = iter.next().transpose()? {
+    println!("{:?}", float_value);
 }
 # Ok(())
 # }
 ```
 
 ### Double
+
 `Double` is represented as rust `f64`
 
 ```rust
@@ -173,11 +180,11 @@ session
     .await?;
 
 // Read a double from the table
-if let Some(rows) = session.query("SELECT a FROM keyspace.table", &[]).await?.rows {
-    for row in rows.into_typed::<(f64,)>() {
-        let (double_value,): (f64,) = row?;
-    }
+let result = session.query("SELECT a FROM keyspace.table", &[]).await?;
+let mut iter = result.rows_typed::<(f64,)>()?;
+while let Some((double_value,)) = iter.next().transpose()? {
+    println!("{:?}", double_value);
 }
 # Ok(())
 # }
-```
+```