orm

问题 I'm trying to create a large SQLite database from around 500 smaller databases (each 50-200MB) to put into Django, and would like to speed up this process. I'm doing this via a custom command. This answer helped me a lot, in reducing the speed to around a minute each in processing a smaller database. However it's still quite a long time. The one thing I haven't done in that answer is to disable database indexing in Django and re-create them. I think this matters for me as my database has few

问题 I want to write a function where a multidimensional array with the following structure: { "id_coretable": 1, "Internal_key": "UPDATED1", "extensiontable_itc": { "description_itc": "UPDATED1" }, "extensiontable_sysops": { "description_sysops": "UPDATED1" } } updates a multidimensional model/collection (i can create either of them, whatever the actual solution to this problem might require) with basically the same structure: { "id_coretable": 1, "Internal_key": "NOTYETUPDATED1", "extensiontable

问题 I want to write a function where a multidimensional array with the following structure: { "id_coretable": 1, "Internal_key": "UPDATED1", "extensiontable_itc": { "description_itc": "UPDATED1" }, "extensiontable_sysops": { "description_sysops": "UPDATED1" } } updates a multidimensional model/collection (i can create either of them, whatever the actual solution to this problem might require) with basically the same structure: { "id_coretable": 1, "Internal_key": "NOTYETUPDATED1", "extensiontable

问题 I am very new to JPA/Hibernate. In my app, I am using Spring Data JPA. I have a requirement to store MultivalueMap in Mysql DB. I have found examples only based on Map, but not MultiValueMap. At first, is that possible to store MultiValueMap in MySQL DB? Second, I will be glad, if someone show me some good example on above. 回答1: You can store Map<K, List<V>> as Set<Map.Entry<K, List<V>>> this way. @Entity public class Entity { //... @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)

问题 I am very new to JPA/Hibernate. In my app, I am using Spring Data JPA. I have a requirement to store MultivalueMap in Mysql DB. I have found examples only based on Map, but not MultiValueMap. At first, is that possible to store MultiValueMap in MySQL DB? Second, I will be glad, if someone show me some good example on above. 回答1: You can store Map<K, List<V>> as Set<Map.Entry<K, List<V>>> this way. @Entity public class Entity { //... @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)

问题 I am working in with a database in which dates are stored as unix time (seconds since 1970). I have the following sql which works as expected: select CONVERT_TZ(FROM_UNIXTIME(creation_date), @@session.time_zone, "Europe/Berlin") from transaction; This is how I tried to do it in Jooq: dsl.select(DSL.date(TRANSACTION.CREATION_DATE) // This does not work .from(TRANSACTION) .fetch(); 回答1: You're using quite a few vendor specific functions there, which are not supported out of the box in jOOQ. As

问题 Imagine I have defined the following custom validator function: isUnique: function () { // This works as expected throw new Error({error:[{message:'Email address already in use!'}]}); } However, when I attempt to query the DB I run into problems: isUnique: function (email) { // This doesn't work var User = seqeulize.import('/path/to/user/model'); User.find({where:{email: email}}) .success(function () { // This gets called throw new Error({error:[{message:'Email address already in use!'}]}); /

问题 I have this query: SELECT COUNT(DISTINCT Serial, DatumOrig, Glucose) FROM values; I've tried to recreate it with SQLAlchemy this way: session.query(Value.Serial, Value.DatumOrig, Value.Glucose).distinct().count() But this translates to this: SELECT count(*) AS count_1 FROM (SELECT DISTINCT values.`Serial` AS `values_Serial`, values.`DatumOrig` AS `values_DatumOrig`, values.`Glucose` AS `values_Glucose` FROM values) AS anon_1 Which does not call the count function inline but wraps the select

问题 I am new to Django and Python and I want to do something I used to do very often in Java EE. Consider the following model (only relevant classes): class Item(models.Model): name = models.CharField(max_length=40) default_price = models.DecimalField(max_digits=6, decimal_places=2, default=50) def __unicode__(self): return self.name class SaleDetail(models.Model): item = models.ForeignKey(Item) deposit = models.ForeignKey(Deposit) quantity = models.PositiveIntegerField() unit_price = models

问题 I have two models. User and Manager User Model const UserMaster = sequelize.define('User', { UserId: { type: DataTypes.BIGINT, allowNull: false, primaryKey: true, autoIncrement: true }, RelationshipId: { type: DataTypes.STRING, allowNull: true, foreignKey: true }, UserName: { type: DataTypes.STRING, allowNull: true } }) Manager model const Manager = sequelize.define('Manager', { ManagerId: { type: DataTypes.BIGINT, allowNull: false, primaryKey: true, autoIncrement: true }, RelationshipId: {