I have MySql table that has a date field with zeroes ("0000-00-00") as its default value (field cannot be null, I can't change table structure). Hibernate doesn't like zero dates and throws exception during read or save.
I managed to make it read records by setting MySql connection setting "zeroDateTimeBehavior=convertToNull" that converts zero dates to nulls while retrieving records. It is all working fine until I try to save the record that has null date - it throws exception that date cannot be null.
So the question is - how to save record through Hibernate so date will appear as zeroes in a table?
Thanks.
I'd try to add an Hibernate Interceptor (API, Doc) and try to implement something in the onSave() method.
The following code may work:
static final Date ZERO_DATE = //0000-00-00
public boolean onSave(Object entity,
Serializable id,
Object[] state,
String[] propertyNames,
Type[] types)
throws CallbackException {
for(int i = 0; i< propertyNames.length; i++) {
if(propertyNames[i].equals("dateFieldName") && state[i]==null) {
state[i] = ZERO_DATE;
return; //or may continue, if there are several such fields.
}
}
}
Ready and working solution for DATE '0000-00-00' and TIME '00:00:00': How to map MySQL DATE '0000-00-00' & TIME '00:00:00' with Hibernate
Thanks Preston for the code and ChssPly76 for useful comments.
Related
I receive a MySql database and one table inside it have a Date column in string format, now I need to build a .Net core server with Pomelo and EF Core and requirement is my server can query data from that table in a range of date, but because Date column of that table is in string format so I don't know how to query it, please help.
Thank you!
You are going to have to get that string into a date in order to query it.
I would probably add a new datetime column to the table and then create a simple console app that reads in each string date, try to parse this as a datetime and save it to the new datetime column.
Then you should see how many rows have valid datetimes and correct the others
Finally, you can then query using Entity Framework
how to convert a string to date in mysql?
As was told here
You can Query string to date
SELECT STR_TO_DATE(yourdatefield, '%m/%d/%Y')
FROM yourtable
With database schema change
If you can (i.e. are allowed) to change the schema of the table in question, then just add a new datetime or date column, copy the data over from the old column to the new one, and drop the column:
ALTER TABLE `YourTable` ADD COLUMN `NewDateColumn` date NOT NULL;
UPDATE `YourTable` SET `NewDateColumn` = STR_TO_DATE(`OldDateColumn`,'%Y-%m-%d');
ALTER TABLE `YourTable` DROP COLUMN `OldDateColumn`;
You can run these statements just using MySQLWorkbench or the commmand line tool. Of course you first test them with a local copy, to see that everything works fine.
With value converter
If you cannot change the schema of the table, then you can still query date ranges from the database, as long as the date strings in the database are in a string format, that sorts alphabetically (e.g. YYYY-MM-DD). In that case, you can just use a value converter in your actual app code and don't need to alter the database at all:
public class SomeModel
{
public int SomeModelId {get; set;}
public DateTime YourDateProperty {get; set;} // <-- the type you want to use in .NET
}
public class Context : DbContext
{
public virtual DbSet<SomeModel> SomeModels { get; set; }
// ...
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<SomeModel>(
entity =>
{
entity.Property(e => e.YourDateProperty)
.HasColumnType("varchar(255)") // <-- the type it has in the database table
.HasConversion(
v => v.ToString(#"yyyy\-MM\-dd"),
v => DateTime.Parse(v, CultureInfo.InvariantCulture));
});
}
}
// Here is how a sample query in your app would look like:
var query = context.SomeModels
.Where(m => m.YourDateProperty >= new DateTime(2020, 9, 1) &&
m.YourDateProperty < new DateTime(2020, 9, 10))
.ToList();
I am trying to update data to a mySQL database using JPA. I have no problem persisting data but flush will not work as expected. I retrieve the id for the login session, set that id (it is the primary key) along with setting the description field that I want merged to the database. I have debugged line by line through this method and all variables contain the expected values. Any ideas or suggestions to overcome this problem are appreciated.
public String update() {
factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
EntityManager em = factory.createEntityManager();
if(true){
em.getTransaction().begin();
String sessionEmail=Util.getEmail();
//Create query to find user passwords matching the inputted name
Query myQuery = em.createQuery("SELECT u FROM BusinessAccount u WHERE u.email=:email");
myQuery.setParameter("email", sessionEmail);
List<BusinessAccount> accounts=myQuery.getResultList();
int intId=accounts.get(0).getId();
businessAccount.setId(intId);
String des=businessAccount.getDescription();
businessAccount.setDescription(des);
em.flush();
addMessage(new FacesMessage(FacesMessage.SEVERITY_INFO,
"User Registration Successful!", null));
return "success";
}
else {
addMessage(new FacesMessage(FacesMessage.SEVERITY_ERROR,
"User Registration Failed!", null));
return "failure";
}
}
merge() persists all the state of the entity. Not just the non-null fields. I it wasn't, you would complain that you want to set some field to null and that merge() ignores it and leaves it as is.
So get an entity from the database, and modify it, instead of only gettings its ID, creating a new entity instance from scratch and only settings some of its fields.
Note that, if you get the entity and modify it inside a single transaction, you don't even have to call merge(): the new state will be made persistent automatically.
i have a complex problem with Date field. Describe what i want to do:
I have field date1 as Date in my db.
#Temporal(TemporalType.DATE)
private Date date1;
I want to take data from this field and compare with current date.
#Query("SELECT date1 FROM Table io WHERE io.date1 >= DATE_FORMAT(CURRENT_DATE, '%Y-%m-%e')")
Date findAll2();
public boolean CheckDate1(){
currentDate = new Date();
date1 = getInterimOrdersRepo().findAll2();
if(currentDate.before(date1) || currentDate.equals(date1)){
System.out.println("TRUE");
System.out.println("currentDate = "+currentDate);
return true;
}
else{
System.out.println("FALSE");
return false;
}
}
but i have an error:
result returns more than one elements; nested exception is javax.persistence.NonUniqueResultException
When method return false i want do Update field data1 with " " empty data.
I using jsf, what i must to do?
It seems that you are trying to read several values from the table into a single variable, and that is the error.
findall2 returns an array (most likely) and u should read one of it's values - try reading first one.
Furthermore, I believe that you can skip the "DATE_FORMAT" in your query, and this is a very strange way to write a code. Not clear what u are trying to achieve here
I have a programme with the following code:
In XXX.java, I set the SVC_APPR_DT_IN_MILLIS with the date value obtained from a record in Oracle database using String.valueOf(date.getTime()) strong text. It is stored as a String:
private void setApprovalDateProperty(Date date) {
setAdditionalProperty(SVC_APPR_DT_IN_MILLIS, String.valueOf(date.getTime()));
}
In YYY.java, I return the Date back by using new Date(Long.valueOf())
private Date getApprovalDate() throws ParseException {
String approvalDateInMillis = this.record
.getAdditionalProperty(XXX.SVC_APPR_DT_IN_MILLIS);
return new Date(Long.valueOf(approvalDateInMillis));
}
For one of the record, It throws below error, where "04/12/2012 14:44:38" is the date of the records in database.
For input string: "04/12/2012 14:44"
java.lang.NumberFormatException: For input string: "04/12/2012 14:44"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Long.parseLong(Long.java:412)
at java.lang.Long.valueOf(Long.java:518)
at YYY.getApprovalDate(YYY.java:634)
I have checked the database, many records in the database can be processed without any problem, except this one. May I know what is the possible cause of this error? I want to simulate the problem but I have no idea how to replicate it. Anyone has any suggestions?
It sounds like one of the records in the database has been inserted with a faulty version, or that the database is corrupt.
Have you checked what the value of approvalDateInMillis is before the call to Long.valueOf?
You could add e.g.
if (!approvalDateInMillis.matches("^[0-9+]$"))
throw new Error(
String.format("Invalid approvalDateInMillis format: '%s'", approvalDateInMillis));
before the return statement and then continue debugging to see what is really in the database.
Not sure if I should raise an issue regarding this, so thought I would ask if anybody knew a simple workaround for this first. I am getting an error when I try to use Dapper with OleDbConnection when used in combination with MS Access 2003 (Jet.4.0) (not my choice of database!)
When running the test code below I get an exception 'OleDbException : Data type mismatch in criteria expression'
var count = 0;
using (var conn = new OleDbConnection(connString)) {
conn.Open();
var qry = conn.Query<TestTable>("select * from testtable where CreatedOn <= #CreatedOn;", new { CreatedOn = DateTime.Now });
count = qry.Count();
}
I believe from experience in the past with OleDb dates, is that when setting the DbType to Date, it then changes internally the value for OleDbType property to OleDbTimeStamp instead of OleDbType.Date. I understand this is not because of Dapper, but what 'could' be considered a strange way of linking internally in the OleDbParameter class
When dealing with this either using other ORMs, raw ADO or my own factory objects, I would clean up the command object just prior to running the command and change the OleDbType to Date.
This is not possible with Dapper as far as I can see as the command object appears to be internal. Unfortunately I have not had time to learn the dynamic generation stuff, so I could be missing something simple or I might suggest a fix and contribute rather than simply raise an issue.
Any thoughts?
Lee
It's an old thread but I had the same problem: Access doesn't like DateTime with milliseconds, so you have to add and extension method like this :
public static DateTime Floor(this DateTime date, TimeSpan span)
{
long ticks = date.Ticks / span.Ticks;
return new DateTime(ticks * span.Ticks, date.Kind);
}
And use it when passing parameters:
var qry = conn.Query<TestTable>("select * from testtable where CreatedOn <= #CreatedOn;", new { CreatedOn = DateTime.Now.Floor(TimeSpan.FromSeconds(1)) });
Unfortunately, with current Dapper version (1.42), we cannot add custom TypeHandler for base types (see #206).
If you can modify Dapper (use the cs file and not the DLL) merge this pull request and then you do not have to use Floor on each parameters :
public class DateTimeTypeHandler : SqlMapper.TypeHandler<DateTime>
{
public override DateTime Parse(object value)
{
if (value == null || value is DBNull)
{
return default(DateTime);
}
return (DateTime)value;
}
public override void SetValue(IDbDataParameter parameter, DateTime value)
{
parameter.DbType = DbType.DateTime;
parameter.Value = value.Floor(TimeSpan.FromSeconds(1));
}
}
SqlMapper.AddTypeHandler<DateTime>(new DateTimeTypeHandler());