Initial commit of iciql.

1 files changed, 236 insertions, 0 deletions

diff --git a/src/com/iciql/SQLDialect.java b/src/com/iciql/SQLDialect.java
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+/*
+ * Copyright 2004-2011 H2 Group.
+ * Copyright 2011 James Moger.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.iciql;
+
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.SQLException;
+
+import com.iciql.TableDefinition.IndexDefinition;
+import com.iciql.util.StatementBuilder;
+import com.iciql.util.StringUtils;
+
+/**
+ * This interface defines points where iciql can build different statements
+ * depending on the database used.
+ */
+public interface SQLDialect {
+
+	/**
+	 * Configure the dialect from the database connection.
+	 * 
+	 * @param conn
+	 */
+	void configureDialect(Connection conn);
+
+	/**
+	 * Returns a properly formatted table name for the dialect.
+	 * 
+	 * @param schema
+	 *            the schema name, or null for no schema
+	 * @param table
+	 *            the properly formatted table name
+	 * @return the SQL snippet
+	 */
+	String prepareTableName(String schema, String table);
+
+	/**
+	 * Returns a properly formatted column name for the dialect.
+	 * 
+	 * @param name
+	 *            the column name
+	 * @return the properly formatted column name
+	 */
+	String prepareColumnName(String name);
+
+	/**
+	 * Get the CREATE INDEX statement.
+	 * 
+	 * @param schema
+	 *            the schema name
+	 * @param table
+	 *            the table name
+	 * @param index
+	 *            the index definition
+	 * @return the SQL statement
+	 */
+	String prepareCreateIndex(String schema, String table, IndexDefinition index);
+
+	/**
+	 * Append "LIMIT limit" to the SQL statement.
+	 * 
+	 * @param stat
+	 *            the statement
+	 * @param limit
+	 *            the limit
+	 */
+	void appendLimit(SQLStatement stat, long limit);
+
+	/**
+	 * Append "OFFSET offset" to the SQL statement.
+	 * 
+	 * @param stat
+	 *            the statement
+	 * @param offset
+	 *            the offset
+	 */
+	void appendOffset(SQLStatement stat, long offset);
+
+	/**
+	 * Whether memory tables are supported.
+	 * 
+	 * @return true if they are
+	 */
+	boolean supportsMemoryTables();
+
+	/**
+	 * Whether merge is a supported function.
+	 * 
+	 * @return true if they are
+	 */
+	boolean supportsMerge();
+
+	/**
+	 * Whether LIMIT/OFFSET notation is supported.
+	 * 
+	 * @return true if they are
+	 */
+	boolean supportsLimitOffset();
+
+	/**
+	 * Default implementation of an SQL dialect.
+	 * Does not support merge nor index creation.
+	 */
+	public static class DefaultSQLDialect implements SQLDialect {
+		float databaseVersion;
+		String productName;
+		String productVersion;
+
+		@Override
+		public String toString() {
+			return getClass().getName() + ": " + productName + " " + productVersion;
+		}
+		
+		@Override
+		public void configureDialect(Connection conn) {
+			loadIdentity(conn);
+		}
+		
+		protected void loadIdentity(Connection conn) {
+			try {
+				DatabaseMetaData data = conn.getMetaData();
+				databaseVersion = Float.parseFloat(data.getDatabaseMajorVersion() + "."
+						+ data.getDatabaseMinorVersion());
+				productName = data.getDatabaseProductName();
+				productVersion = data.getDatabaseProductVersion();
+			} catch (SQLException e) {
+				throw new IciqlException(e);
+			}
+		}		
+
+		@Override
+		public boolean supportsMemoryTables() {
+			return false;
+		}
+
+		@Override
+		public boolean supportsMerge() {
+			return false;
+		}
+		
+		@Override
+		public boolean supportsLimitOffset() {
+			return true;
+		}
+
+		@Override
+		public String prepareTableName(String schema, String table) {
+			if (StringUtils.isNullOrEmpty(schema)) {
+				return table;
+			}
+			return schema + "." + table;
+		}
+
+		@Override
+		public String prepareColumnName(String name) {
+			return name;
+		}
+
+		@Override
+		public String prepareCreateIndex(String schema, String table, IndexDefinition index) {
+			throw new IciqlException("Dialect does not support index creation!");
+		}
+
+		@Override
+		public void appendLimit(SQLStatement stat, long limit) {
+			stat.appendSQL(" LIMIT " + limit);
+		}
+
+		@Override
+		public void appendOffset(SQLStatement stat, long offset) {
+			stat.appendSQL(" OFFSET " + offset);
+		}
+	}
+	
+
+	/**
+	 * H2 database dialect.
+	 */
+	public static class H2Dialect extends DefaultSQLDialect {
+
+		@Override
+		public boolean supportsMemoryTables() {
+			return true;
+		}
+
+		@Override
+		public boolean supportsMerge() {
+			return true;
+		}
+		
+		@Override
+		public String prepareCreateIndex(String schema, String table, IndexDefinition index) {
+			StatementBuilder buff = new StatementBuilder();
+			buff.append("CREATE ");
+			switch (index.type) {
+			case STANDARD:
+				break;
+			case UNIQUE:
+				buff.append("UNIQUE ");
+				break;
+			case HASH:
+				buff.append("HASH ");
+				break;
+			case UNIQUE_HASH:
+				buff.append("UNIQUE HASH ");
+				break;
+			}
+			buff.append("INDEX IF NOT EXISTS ");
+			buff.append(index.indexName);
+			buff.append(" ON ");
+			buff.append(table);
+			buff.append("(");
+			for (String col : index.columnNames) {
+				buff.appendExceptFirst(", ");
+				buff.append(col);
+			}
+			buff.append(")");
+			return buff.toString();
+		}
+	}
+}

path: root/src/com/iciql/SQLDialect.java