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Merge pull request #45239 from Avogar/generate-random

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Ilya Yatsishin 2023-01-15 00:37:34 +01:00 committed by GitHub
commit 96987b7cd8
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6 changed files with 43 additions and 9 deletions
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13
docs/en/sql-reference/table-functions/generate.md
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@ -39,3 +39,16 @@ SELECT * FROM generateRandom('a Array(Int8), d Decimal32(4), c Tuple(DateTime64(
│ [68] │ -67417.0770 │ ('2080-03-12 14:17:31.269','110425e5-413f-10a6-05ba-fa6b3e929f15') │
└──────────┴──────────────┴────────────────────────────────────────────────────────────────────┘
```
```sql
CREATE TABLE random (a Array(Int8), d Decimal32(4), c Tuple(DateTime64(3), UUID)) engine=Memory;
INSERT INTO random SELECT * FROM generateRandom() LIMIT 2;
SELECT * FROM random;
```
```text
┌─a────────────────────────────┬────────────d─┬─c──────────────────────────────────────────────────────────────────┐
│ [] │ 68091.8197 │ ('2037-10-02 12:44:23.368','039ecab7-81c2-45ee-208c-844e5c6c5652') │
│ [8,-83,0,-22,65,9,-30,28,64] │ -186233.4909 │ ('2062-01-11 00:06:04.124','69563ea1-5ad1-f870-16d8-67061da0df25') │
└──────────────────────────────┴──────────────┴────────────────────────────────────────────────────────────────────┘
```

18
src/TableFunctions/TableFunctionGenerateRandom.cpp
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@ -25,6 +25,7 @@ namespace ErrorCodes
extern const int BAD_ARGUMENTS;
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
extern const int LOGICAL_ERROR;
extern const int CANNOT_EXTRACT_TABLE_STRUCTURE;
}
void TableFunctionGenerateRandom::parseArguments(const ASTPtr & ast_function, ContextPtr /*context*/)
@ -37,9 +38,7 @@ void TableFunctionGenerateRandom::parseArguments(const ASTPtr & ast_function, Co
ASTs & args = args_func.at(0)->children;
if (args.empty())
throw Exception("Table function '" + getName() + "' requires at least one argument: "
" structure, [random_seed, max_string_length, max_array_length].",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
return;
if (args.size() > 4)
throw Exception("Table function '" + getName() + "' requires at most four arguments: "
@ -77,12 +76,23 @@ void TableFunctionGenerateRandom::parseArguments(const ASTPtr & ast_function, Co
ColumnsDescription TableFunctionGenerateRandom::getActualTableStructure(ContextPtr context) const
{
if (structure == "auto")
{
if (structure_hint.empty())
throw Exception(
ErrorCodes::CANNOT_EXTRACT_TABLE_STRUCTURE,
"Table function '{}' was used without structure argument but structure could not be determined automatically. Please, "
"provide structure manually",
getName());
return structure_hint;
}
return parseColumnsListFromString(structure, context);
}
StoragePtr TableFunctionGenerateRandom::executeImpl(const ASTPtr & /*ast_function*/, ContextPtr context, const std::string & table_name, ColumnsDescription /*cached_columns*/) const
{
auto columns = getActualTableStructure(context);
ColumnsDescription columns = getActualTableStructure(context);
auto res = std::make_shared<StorageGenerateRandom>(
StorageID(getDatabaseName(), table_name), columns, String{}, max_array_length, max_string_length, random_seed);
res->startup();

12
src/TableFunctions/TableFunctionGenerateRandom.h
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@ -5,7 +5,7 @@
namespace DB
{
/* generateRandom(structure, [max_array_length, max_string_length, random_seed])
/* generateRandom([structure, max_array_length, max_string_length, random_seed])
* - creates a temporary storage that generates columns with random data
*/
class TableFunctionGenerateRandom : public ITableFunction
@ -13,7 +13,11 @@ class TableFunctionGenerateRandom : public ITableFunction
public:
static constexpr auto name = "generateRandom";
std::string getName() const override { return name; }
bool hasStaticStructure() const override { return true; }
bool hasStaticStructure() const override { return structure != "auto"; }
bool needStructureHint() const override { return structure == "auto"; }
void setStructureHint(const ColumnsDescription & structure_hint_) override { structure_hint = structure_hint_; }
private:
StoragePtr executeImpl(const ASTPtr & ast_function, ContextPtr context, const std::string & table_name, ColumnsDescription cached_columns) const override;
const char * getStorageTypeName() const override { return "GenerateRandom"; }
@ -21,11 +25,11 @@ private:
ColumnsDescription getActualTableStructure(ContextPtr context) const override;
void parseArguments(const ASTPtr & ast_function, ContextPtr context) override;
String structure;
String structure = "auto";
UInt64 max_string_length = 10;
UInt64 max_array_length = 10;
std::optional<UInt64> random_seed;
ColumnsDescription structure_hint;
};

2
tests/queries/0_stateless/01256_negative_generate_random.sql
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@ -1,5 +1,5 @@
SELECT * FROM generateRandom('i8', 1, 10, 10); -- { serverError 62 }
SELECT * FROM generateRandom; -- { serverError 60 }
SELECT * FROM generateRandom(); -- { serverError 42 }
SELECT * FROM generateRandom(); -- { serverError CANNOT_EXTRACT_TABLE_STRUCTURE }
SELECT * FROM generateRandom('i8 UInt8', 1, 10, 10, 10, 10); -- { serverError 42 }
SELECT * FROM generateRandom('', 1, 10, 10); -- { serverError 62 }

1
tests/queries/0_stateless/02533_generate_random_schema_inference.reference Normal file
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@ -0,0 +1 @@
10

6
tests/queries/0_stateless/02533_generate_random_schema_inference.sql Normal file
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@ -0,0 +1,6 @@
drop table if exists test;
create table test (x UInt32, y String) engine=Memory;
insert into test select * from generateRandom() limit 10;
select count() from test;
drop table test;