Transaction, transaction flow

api/src/main/java/me/zort/sqllib/api/Query.java

@@ -1,5 +1,7 @@
 package me.zort.sqllib.api;
 
+import java.sql.SQLException;
+
 /**
  * This class represents a query.
  * @author ZorTik
@@ -21,4 +23,6 @@ default boolean isAncestor() {
         return getAncestor() == this;
     }
 
+    default void errorSignal(SQLException e) {}
+
 }

api/src/main/java/me/zort/sqllib/api/data/QueryRowsResult.java

@@ -2,10 +2,10 @@
 
 import lombok.Getter;
 
-import java.util.ArrayList;
+import java.util.LinkedList;
 
 @Getter
-public class QueryRowsResult<T> extends ArrayList<T> implements QueryResult {
+public class QueryRowsResult<T> extends LinkedList<T> implements QueryResult {
 
     private final boolean successful;
     private String rejectMessage = null;

core/src/main/java/me/zort/sqllib/SQLConnectionBuilder.java

@@ -8,6 +8,7 @@
 import me.zort.sqllib.internal.factory.SQLConnectionFactory;
 import me.zort.sqllib.internal.impl.DefaultSQLEndpoint;
 import me.zort.sqllib.internal.impl.SQLEndpointImpl;
+import me.zort.sqllib.pool.SQLConnectionPool;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -16,6 +17,7 @@
 import java.sql.SQLException;
 import java.util.Objects;
 
+@SuppressWarnings("unused")
 public final class SQLConnectionBuilder implements Cloneable {
 
     public static @NotNull SQLConnectionBuilder of(String address, int port, String database, String username, String password) {
@@ -27,15 +29,11 @@ public final class SQLConnectionBuilder implements Cloneable {
     }
 
     public static @NotNull SQLConnectionBuilder ofSQLite(String path) {
-        SQLConnectionBuilder builder = of(new SQLEndpointImpl("jdbc:sqlite:" + path, null, null));
-        builder.withDriver("org.sqlite.JDBC");
-        return builder;
+        return of(new SQLEndpointImpl("jdbc:sqlite:" + path, null, null)).withDriver("org.sqlite.JDBC");
     }
 
     public static SQLConnectionBuilder of(SQLEndpoint endpoint) {
-        if(!endpoint.isValid()) {
-            throw new SQLEndpointNotValidException(endpoint);
-        }
+        if(!endpoint.isValid()) throw new SQLEndpointNotValidException(endpoint);
         return new SQLConnectionBuilder(endpoint);
     }
 
@@ -53,9 +51,7 @@ public SQLConnectionBuilder(@NotNull String address, int port, @NotNull String d
 
     public SQLConnectionBuilder(@Nullable SQLEndpoint endpoint) {
         this.endpoint = endpoint;
-        this.jdbc = endpoint != null
-                ? endpoint.buildJdbc()
-                : null;
+        this.jdbc = endpoint != null ? endpoint.buildJdbc() : null;
     }
 
     public @NotNull SQLConnectionBuilder withEndpoint(final SQLEndpoint endpoint) {
@@ -65,10 +61,7 @@ public SQLConnectionBuilder(@Nullable SQLEndpoint endpoint) {
     }
 
     public @NotNull SQLConnectionBuilder withParam(final @NotNull String key, final @NotNull String value) {
-        if (endpoint != null) {
-            jdbc += (jdbc.contains("?") ? "&" : "?");
-            jdbc += key + "=" + value;
-        }
+        if (endpoint != null) jdbc += (jdbc.contains("?") ? "&" : "?") + (key + "=" + value);
         return this;
     }
 
@@ -92,11 +85,13 @@ public SQLConnectionBuilder(@Nullable SQLEndpoint endpoint) {
             driver = Constants.DEFAULT_DRIVER;
         }
         SQLConnectionFactory connectionFactory = new BuilderSQLConnectionFactory(this, driver);
-        if(jdbc.contains("jdbc:sqlite")) {
-            return new SQLiteDatabaseConnectionImpl(connectionFactory, options);
-        } else {
-            return new SQLDatabaseConnectionImpl(connectionFactory, options);
-        }
+        return jdbc.contains("jdbc:sqlite")
+                ? new SQLiteDatabaseConnectionImpl(connectionFactory, options)
+                : new SQLDatabaseConnectionImpl(connectionFactory, options);
+    }
+
+    public @NotNull SQLConnectionPool createPool(final @NotNull SQLConnectionPool.Options options) {
+        return new SQLConnectionPool(this, options);
     }
 
     @Override

core/src/main/java/me/zort/sqllib/SQLDatabaseConnection.java

@@ -1,6 +1,7 @@
 package me.zort.sqllib;
 
 import lombok.AllArgsConstructor;
+import lombok.Data;
 import lombok.Getter;
 import me.zort.sqllib.api.Query;
 import me.zort.sqllib.api.SQLConnection;
@@ -12,6 +13,8 @@
 import me.zort.sqllib.internal.impl.QueryResultImpl;
 import me.zort.sqllib.internal.query.*;
 import me.zort.sqllib.internal.query.part.SetStatement;
+import me.zort.sqllib.transaction.Transaction;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -41,6 +44,12 @@ public SQLDatabaseConnection(final @NotNull SQLConnectionFactory connectionFacto
         SQLConnectionRegistry.register(this);
     }
 
+    /**
+     * @deprecated Use {@link SQLDatabaseConnection#createProxy(Class)} instead.
+     */
+    @Deprecated
+    public abstract <T> T createGate(Class<T> mappingInterface);
+
     /**
      * Constructs a mapping repository based on provided interface.
      * The interface should follow rules for creating mapping repositories
@@ -72,8 +81,8 @@ public SQLDatabaseConnection(final @NotNull SQLConnectionFactory connectionFacto
      * @return Mapping repository.
      * @param <T> Type of mapping repository.
      */
-    public abstract <T> T createGate(Class<T> mappingInterface);
-    public abstract <T> T createGate(Class<T> mappingInterface, @NotNull StatementMappingOptions options);
+    public abstract <T> T createProxy(Class<T> mappingInterface);
+    public abstract <T> T createProxy(Class<T> mappingInterface, @NotNull StatementMappingOptions options);
     public abstract boolean buildEntitySchema(String tableName, Class<?> entityClass);
 
     /**
@@ -112,27 +121,21 @@ public SQLDatabaseConnection(final @NotNull SQLConnectionFactory connectionFacto
      */
     public abstract QueryResult exec(Query query);
     public abstract QueryResult exec(String query);
+    @ApiStatus.Experimental
+    public abstract Transaction beginTransaction();
+    @ApiStatus.Experimental
+    public abstract void closeTransaction();
+    @ApiStatus.Experimental
+    @Nullable
+    public abstract Transaction getTransaction();
+    public abstract boolean isTransactionActive();
     protected abstract DefsVals buildDefsVals(Object obj);
     public abstract boolean isLogSqlErrors();
     public abstract boolean isDebug();
 
-    /**
-     * Saves this mapping object into database using upsert query.
-     * <p>
-     * All mapping strategies are described in:
-     * {@link SQLDatabaseConnection#query(Query, Class)}.
-     *
-     * @param table Table to save into.
-     * @param obj The object to save.
-     * @return Result of the query.
-     */
-    // by default, it creates and upsert request.
-    public QueryResult save(final @NotNull String table, final @NotNull Object obj) {
-        DefsVals defsVals = buildDefsVals(obj);
-
-        if(defsVals == null) return new QueryResultImpl(false);
-
-        return save(obj).table(table).execute();
+    public UpsertQuery save(final @NotNull String table, final @NotNull Object obj) {
+        if(buildDefsVals(obj) == null) throw new IllegalArgumentException("Cannot create save query! (defsVals == null)");
+        return save(obj).table(table);
     }
 
     public UpsertQuery save(final @NotNull Object obj) {
@@ -240,4 +243,10 @@ protected static class DefsVals {
         private final String[] defs;
         private final SQLDatabaseConnectionImpl.UnknownValueWrapper[] vals;
     }
+
+    @AllArgsConstructor
+    @Data
+    public static class UnknownValueWrapper {
+        private Object object;
+    }
 }