Что такое data type ошибка

ORA-00902: incorrect datatype error occurs when a column is declared with an invalid data type that Oracle does not support. when creating a table, altering a table, or declaring a variable in PL/SQL. The create table command creates a collection of columns with the data types given. The data type must be one that is supported by Oracle. Oracle will throw an incorrect data type error if any other data type is specified.

Oracle does not support data types such as boolean, string, and so on. If you attempt to create a table with one or more columns of an unsupported data type, Oracle is unable to determine the data type. As a result, Oracle will display the error message ORA-00902: incorrect datatype.

When this ORA-00902 error occurs

If you create a table with a column declared with an unsupported data type or alter a table with an unsupported data type, the error ORA-00902: incorrect datatype will be shown. The columns in a table must be declared with oracle supported data types.

CREATE TABLE EMP(
id numbers, 
name VARCHAR2(100)
)

Error

Error starting at line : 4 in command -
CREATE TABLE EMP(
id numbers, 
name VARCHAR2(100)
)
Error report -
ORA-00902: invalid datatype
00902. 00000 -  "invalid datatype"

Root Cause

Oracle supports a number of data types that may be declared and used in an Oracle database. Oracle also provides the option of creating a user-defined data type. Oracle will not recognize an unsupported data type if a table contains one or more columns with unsupported data types. When creating or altering a table, Oracle will give an error stating that an incorrect data type was detected.

Solution 1

If an unsupported data type is defined when creating or altering a table, replace the data type to an Oracle supported data type. Check to see if an Oracle data type is supported by a certain Oracle version. Change the data type to one that is supported by the Oracle version. This will address the problem.

Problem

CREATE TABLE EMP(
id numbers, 
name VARCHAR2(100)
)

Error report -
ORA-00902: invalid datatype
00902. 00000 -  "invalid datatype"

Solution

CREATE TABLE EMP(
id number, 
name VARCHAR2(100)
)

Solution 2

The data types supported by Oracle are as follows. The list may differ from one Oracle version to another. Check to see if the Oracle version you’re using is supported.

Character data types

char(size), nchar(size)
varchar2(size), nvarchar2(size)
long
raw, long raw

Numeric data types

number(precision, scale), numeric(precision, scale),
integer, int, smallint,
real,  double, double precision,
float, dec(precision, scale), decimal(precision, scale)

Date data types

date, timestamp

Large Object Data types

blob, clob, nclob, bfile

Rowid data type

rowid, nrowid

While I started learning JavaScript, I faced a problem often. I’ve seen many of the learners facing a common problem at the beginning of learning JavaScript. I want to share that with my readers in this post.

Data Types in JavaScript

JavaScript recognizes:
6 immutable data types: Boolean, Null, Undefined, Number, String & Symbol.
1 type for mutable items: Object

Let me show you an example first:

let nine = 9; //data type : Number
let three = "3"; //data type : String

let summation = nine + three; //expected output: 9+3=12

console.log(summation) //output: 93

We all know that the summation of 9 and 3 is 12. But here, the actual output shows a different result, that is 93, which means there must be some error in the code.

The reason of this wrong output is, the variable nine is assigned with the value 9 which is a number and the variable three is assigned with the value 3 which is a string.

A basic information about JavaScript is, when we add two and different data types with + operator , it actually concatenates them, doesn’t return a summation!

If you + two strings, it will return the concatenation of them but if you + two numbers they will return the sum. That’s why, The variable summation returned a concatenated value 93, not the actual summation 12.

Now that we’ve seen this problem, let’s try to solve it.
It may happen often that, maybe you’re in hurry and you just mistakenly used quotation marks («») around a number while assigning it to a variable. This mistake will turn the number data type into a string data type as we saw in the example above.

To check why the unexpected output has occurred, we can debug the problem.

In JavaScript, typeof is useful in debugging while working with multiple data types. typeof is used to check the data structure or type of a variable.

Type errors and unexpected outputs may occur if the data types are not similar, especially when you’re accessing data in the form of JSON (JavaScript Object Notation) Object.

Some examples of using typeof while debugging are:
1) console.log(typeof » «) //output String
2) console.log(typeof 7) //output Number
3) console.log(typeof {}) //output Object
4) console.log(typeof []) //output Object

(Note that, in JavaScript, Arrays are also technically one type of Object)

Let’s see the previous example and how to debug it with typeof :

let nine = 9; //data type : Number
let three = "3"; //data type : String
let summation = nine + three; //expected output: 9+3=12

console.log(summation) //output: 93
console.log(typeof nine); //output: number
console.log(typeof three); //output string

Now, we can easily know where we have mistaken and simply change the string to number.
Then everything will work as we desired.

The changed and correct output will be:

let nine = 9; //data type : Number
let three = 3; //data type : Number
let summation = nine + three; //output: 9+3=12

Now that I have explain the reason of the wrong output, I have a problem for you to solve.

let nine = 9; 
let five =5;
let three = "3"; 
let two = "2";

let summation = nine + three + five + two; 
let sum = nine + five + three + two;

console.log(summation);
console.log(sum);

Can you tell me what summation and sum will return and why?

Hint: check the data types carefully and also the sequence of the variables in the summation and sum.

You can explain your answer in the discussion section.

When I run this code I get the output:

TypeError: an integer is required

I have no idea why this is happening because I set both of the data types to uint8 and uint64 respectively. Evidently I don’t understand data types very well.

from PIL import Image

from numpy import random

N = 100

##open an image
im=Image.open('/Users/grahamwarner/Desktop/Experiment/gwarner/labeled_photos/masks/003030.png')

##create a random image
rand_matrix = random.randint(0, 255, (500, 500, 3)).astype('uint8')

rand_image = Image.fromarray(rand_matrix)

##select N random pixels
rand_pix = random.randint(0,499, (N,2)).astype('uint64')

##replace the random values at these pixels with the original values
for ii in range(N):

  rand_image.putpixel(tuple(rand_pix[ii,:]), im.getpixel(tuple(rand_pix[ii,:])))