我正在开发一个使用WebSQL存储历史数据的Chrome扩展程序。 作为WebSQL，数据库存储在客户端上。
我想添加一个导出/导入此类数据的选项，以便用户可以与其他用户或其他PC共享/使用此数据。
这是我在仅客户端数据库上的第一步，所以我想知道如何做到这一点。
我想将数据库转换为一个巨大的json字符串，用户可以复制/粘贴，但看起来不是非常用户友好。
有没有更好的解决方案？
答案 0 :(得分：16)
我在几天前写的HTML5 database client上有一个表转储解决方案。
查看http://html5db.desalasworks.com/script.js并向下滚动到SqlClient.exportTable，这个示例需要扩展以涵盖整个数据库。
步骤如下：
第1步：创建架构：
SELECT sql FROM sqlite_master
第2步：获取表格列表：
SELECT tbl_name from sqlite_master WHERE type = 'table'
步骤3：遍历每个步骤并使用结果
创建INSERT脚本transaction.executeSql("SELECT * FROM " + _tbl_name + ";", [],
function(transaction, results) {
if (results.rows) {
for (var i = 0; i < results.rows.length; i++) {
var row = results.rows.item(i);
var _fields = [];
var _values = [];
for (col in row) {
_fields.push(col);
_values.push('"' + row[col] + '"');
}
_exportSql += ";\nINSERT INTO " + _tbl_name + "(" + _fields.join(",") + ") VALUES (" + _values.join(",") + ")";
}
}
}
);
希望这很有用。
2016年1月更新 - 整个数据库导出
我有一个JS websqldump库，您也可以从github下载。
这个将导出整个数据库。查看以下代码：
https://github.com/sdesalas/websqldump
用法如下
websqldump.export({
database: 'NorthwindLite',
success: function(sql) {alert(sql);}
});
答案 1 :(得分：-1)
不是最优雅的方式，但最方便 只需将脚本粘贴到chrome调试工具中，然后调用c（），就可以获得该文件。
var looongSQL = "";
var x = function (options) {
if (options.n < options.sqlTables.length) {
onTheMove.openLocalDatabase().transaction(
function (tx) {
var sqlStatement = "SELECT * FROM " + options.sqlTables[options.n];
tx.executeSql(sqlStatement, [],
function (tx, rslt) {
if (rslt.rows) {
for (var m = 0; m < rslt.rows.length; m++) {
var dataRow = rslt.rows.item(m);
var _fields = [];
var _values = [];
for (col in dataRow) {
_fields.push(col);
_values.push('"' + dataRow[col] + '"');
}
looongSQL += "INSERT INTO " + options.sqlTables[options.n] + "(" + _fields.join(",") + ") VALUES (" + _values.join(",") + ");\n";
}
}
options.n++;
x(options);
}
);
});
}else
{
document.location = 'data:Application/octet-stream,' +
encodeURIComponent(looongSQL);
}
};
var c = function () {
onTheMove.openLocalDatabase().transaction(
function (transaction) {
transaction.executeSql("SELECT sql FROM sqlite_master;", [],
function (transaction, results) {
var sqlStatements = [];
if (results.rows) {
for (var i = 0; i < results.rows.length; i++) {
console.log(results.rows.item(i));
var row = results.rows.item(i);
if (row.sql != null && row.sql.indexOf("CREATE TABLE ") != -1 && row.sql.indexOf("__") == -1) {
var tableName = row.sql.replace("CREATE TABLE ", "").split(/ |\(/)[0];
sqlStatements.push('DROP TABLE IF EXISTS ' + tableName);
}if(row.sql != null && row.sql.indexOf("__") == -1){
sqlStatements.push(row.sql);}
}
}
for (var j = 0; j < sqlStatements.length; j++) {
if (sqlStatements[j] != null) {
looongSQL += sqlStatements[j] + ';\r\n';
}
}
transaction.executeSql("SELECT tbl_name from sqlite_master WHERE type = 'table'", [],
function (transaction, res) {
var sqlTables = [];
for (var k = 0; k < res.rows.length; k++) {
if (res.rows.item(k).tbl_name.indexOf("__") == -1) {
sqlTables.push(res.rows.item(k).tbl_name);
}
}
x({
sqlTables: sqlTables,
n: 0
});
});
}
);
});
};
将其导出为JSON
的另一个版本var looongSQL = "[\n";
var stringidiedLocalStorage = JSON.stringify(JSON.stringify(localStorage));
looongSQL += "/* 1 */ " + stringidiedLocalStorage + ",\n";
var x = function (options) {
if (options.n < options.sqlTables.length) {
onTheMove.openLocalDatabase().transaction(
function (tx) {
var sqlStatement = "SELECT * FROM " + options.sqlTables[options.n];
tx.executeSql(sqlStatement, [],
function (tx, rslt) {
if (rslt.rows && rslt.rows.length > 0) {
var _fields = [];
for (var col in rslt.rows.item(0)) {
_fields.push(col);
}
var insertTableSQL = "\"INSERT INTO " + options.sqlTables[options.n] + "(" + _fields.join(",") + ") ";
looongSQL += "/* " + options.count + " */ " + insertTableSQL;
for (var m = 0; m < rslt.rows.length; m++) {
var dataRow = rslt.rows.item(m);
var _values = [];
for (var col in dataRow) {
_values.push('\'' + dataRow[col] + '\'');
}
looongSQL += "SELECT " + _values.join(",");
if (m < rslt.rows.length - 1 && (m % 499 != 0 || m == 0)) {
looongSQL += " UNION ALL ";
}
if (m % 499 == 0 && m != 0) {
options.count++;
looongSQL += "\",\r\n/* " + options.count + " */ " + insertTableSQL;
}
}
looongSQL += "\",\r\n";
options.count++;
}
options.n++;
x(options);
}
);
});
} else {
looongSQL += ']';
document.location = 'data:Application/octet-stream,' +
encodeURIComponent(looongSQL);
}
};
var c = function () {
onTheMove.openLocalDatabase().transaction(
function (transaction) {
transaction.executeSql("SELECT sql FROM sqlite_master;", [],
function (transaction, results) {
var sqlStatements = [];
var count = 2;
if (results.rows) {
for (var i = 0; i < results.rows.length; i++) {
console.log(results.rows.item(i));
var row = results.rows.item(i);
if (row.sql != null && row.sql.indexOf("CREATE ") != -1) {
var objectType = row.sql.replace("CREATE ", "").split(/ |\(/)[0];
if (row.sql.indexOf("CREATE " + objectType + " ") != -1 && row.sql.indexOf("__") == -1) {
var objectName = row.sql.replace("CREATE " + objectType + " ", "").split(/ |\(/)[0];
sqlStatements.push('/* ' + count + ' */ "DROP ' + objectType + ' IF EXISTS ' + objectName + '"');
count++;
}
if (row.sql != null && row.sql.indexOf("__") == -1) {
sqlStatements.push('/* ' + count + ' */ "' + row.sql.replace(/(\r\n|\n|\r)/gm, " ") + '"');
count++;
}
}
}
}
for (var j = 0; j < sqlStatements.length; j++) {
if (sqlStatements[j] != null) {
looongSQL += sqlStatements[j] + ',\r\n';
}
}
transaction.executeSql("SELECT tbl_name from sqlite_master WHERE type = 'table'", [],
function (transaction, res) {
var sqlTables = [];
for (var k = 0; k < res.rows.length; k++) {
if (res.rows.item(k).tbl_name.indexOf("__") == -1) {
sqlTables.push(res.rows.item(k).tbl_name);
}
}
x({
sqlTables: sqlTables,
n: 0,
count: count
});
});
}
);
});
};