h2-insert语句流程分析

java 
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INSERT INTO TEST(ID, NAME) VALUES(3000, 'aaa');

解析得到Insert命令

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org.h2.jdbc.JdbcStatement#execute(java.lang.String)
	->org.h2.jdbc.JdbcStatement#executeInternal
		->org.h2.jdbc.JdbcConnection#prepareCommand(java.lang.String, int)
			->org.h2.engine.Session#prepareCommand
				->org.h2.engine.Session#prepareLocal
					->org.h2.command.Parser#prepareCommand
						->org.h2.command.Parser#parse(java.lang.String)
							->org.h2.command.Parser#parse(java.lang.String, boolean)
								->org.h2.command.Parser#parsePrepared
									->org.h2.command.Parser#parseInsert

关键步骤是进入 org.h2.command.Parser#parseInsert 新建了一个Insert命令

  • 校验insert的表是否存在

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    private Table readTableOrView(String tableName) {
         if (schemaName != null) {
             Table table = getSchema().resolveTableOrView(session, tableName);
             if (table != null) {
                 return table;
             }
         } else {
             //首先查看 PUBLIC Schema里的tablesAndViews 是否存在key为tableName
             Table table = database.getSchema(session.getCurrentSchemaName())
                     .resolveTableOrView(session, tableName);
             if (table != null) {
                 return table;
             }
             //遍历该session对应Schema 中tablesAndViews 是否存在key为tableName
             String[] schemaNames = session.getSchemaSearchPath();
             if (schemaNames != null) {
                 for (String name : schemaNames) {
                     Schema s = database.getSchema(name);
                     table = s.resolveTableOrView(session, tableName);
                     if (table != null) {
                         return table;
                     }
                 }
             }
         }
         if (isDualTable(tableName)) {
             return new DualTable(database);
         }
         //不存在则抛异常 不能insert一个数据库不存在的表吧^_^
         throw DbException.get(ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1, tableName);
     }