Add parsing (incl. validation)

Ensure identifiers start with alphabetical character

Rename parse_variable_name -> parse_column_name

Add DB value parsers and condition parser placeholder

Fix number parser, basic condition parser

Move select parser to select module

Add create statement parser

Move condition parser to common; add delete statement parser

Add drop statement parser

Add insert parser

Add update parser, combine operation parsers into one

Add initial validation, fix compiler warnings

Validation WIP

Allow more spaces in create statement, update TableSchema struct

Add create index parser and validator

Add todo in parse_identifier

Rework the new structure, many other changes

client/src/main.rs

@@ -31,7 +31,7 @@ async fn main() -> anyhow::Result<()> {
         query: "SELECT * FROM users;".to_string().into(),
     })).await?;
     writer.flush().await?;
-
+    let mut line = String::new();
     loop {
         let msg: BackendMessage = reader.read_proto().await?;
         match msg {
@@ -46,7 +46,17 @@ async fn main() -> anyhow::Result<()> {
             },
             BackendMessage::ReadyForQuery(data) => {
                 println!("Ready for query: {:?}", data);
-                break;
+                line.clear();
+                let res = std::io::stdin().read_line(&mut line);
+                if let Ok(_) = res {
+                    if line.eq("exit") {
+                        break;
+                    }
+                    writer.write_proto(FrontendMessage::Query(QueryData {
+                        query: line.clone().into(),
+                    })).await?;
+                    writer.flush().await?;
+                }
             },
             m => {
                 println!("Unexpected message: {:?}", m);